Home

Avia Tablet Accessory Avaya Custom Edition User's Manual

1. Based on Existing Internet Standards sent S Tlga Although SIP may seem new it s actually based on many protocols that are widely used today across the Internet and in many enterprise applications The IETF community took Internet standards as a model and used a text based request response model at the heart of the SIP protocol If you use Web browsers and who doesn t then you already depend on a protocol very similar to SIP called HTTP HyperText Transport Protocol yep that bit before a stan dard Web address that you usually take for granted SIP is modeled after HTTP and in fact uses much of HTTP s syntax and semantics Both are fext encoded protocols which means that they are easy to read and debug This readability pro motes integration across a decentralized architecture such as the Internet and interoperability across a distributed net work In effect SIP is to converged communications what HTTP is to information exchange for the World Wide Web WWW it makes the communications infrastructure transparent to end users and enables ready access to many modes of communication Just as pointing your browser to an HTTP site enables you to play video download pictures or upload files SIP too has been designed to support multi media communications SIP goes beyond HTTP by embedding in communications the intelligence to sense the media capabilities of the end device as well as the availability of a user
2. A user typically has just one SIP AOR such as eileendover domain Then each of the user s devices has its own URI such as sip 408 555 1214 company com user fax SIP business cards One nifty benefit of SIP is how easy it makes the transition for end users who are still using traditional communica tions devices like um telephones For example imagine professors at a uni versity who want to make it easier for their colleagues including researchers at other universities to contact them To do so they are replacing multiple contact numbers on their business cards with a single easy to remember SIP address The problem The univer sity has started to deploy SIP but most of the professors are still using tradi tional analog phones and a complete update to SIP is still years away As a solution Avaya Handle Based Dialing works with the university s Lightweight Directory Access Protocol LDAP directory server to reach any non SIP phones by translating the SIP AOR in real time to a standard telephone number Now the professors can hand out their business cards and be reached at their existing phone through one simple address such as SIP CoolestProf oncampus edu Part 3 explains how you can also still dial this number on a traditional phone SP ih ee 16 SIP Communications For Dummies Avaya Custom Edition Because a SIP URI supports both numeric phone numbers and alphanumeric Internet
3. SIP guide ________ Part 4 How SIP Transforms Enterprise Communications 35 Marveling at what a SIP trunk can carry SIP technology can alter the way that a retail business services its customers Suppose a retailer with a number of store locations wants to offload the task of handling phone calls from its store employees so they can focus on in store customers but the retailer has no direct connectivity between its call center and each store SIP based trunking enables a reconfig uration of communications to address the problem Through SIP based DID mobility inbound service the service store over the SIP network directly to the call center Without making any changes to the local stores the retailer is now able to free up store employees to serve in store customers improve customer service over the phone by reducing hold times and busy signals and still retain a local presence to its cus tomers through a local access number And with SIP trunking the call center can replace dozens of TDM trunk lines with a single SIP link provider transports local calls to each Traditional network model Before SIP and VoIP enterprises connected their internal PBX based telephone systems to carriers via dedicated TDM Time Division Multiplexing trunks Companies paid for them whether they were idle or overflowing and incurred toll and tariff charges especially expensive for long distance calls Today many compa
4. What are the obstaclesstp gbigeinterconnection To enjoy the full benefits of SIP you need to overcome three main barriers S TECy lt a ORUN ________ Part 4 How SIP Transforms Enterprise Communications 39 1 Enabling SIP islands to discover the existence of one another Ensuring that the two islands interoperate 1 Managing and controlling this interconnection so that spam and abuse does not become rampant One answer to all of the above issues is federation Federation is the mechanism by which you your company can provide end to end SIP communications for end users Federation builds a network of open communications within the ecosystem of SIP communications Accomplishing this interconnectivity may require one or more of these processes y A federation service provides discovery services enabling other SIP islands to be discovered from just a telephone number or address A number of databases and directories are available today One such database is ENUM which is described in the next section Mapping Phone Numbers to URIs 1 A federation service built on top of SIP provides interop erability over a wide range of services and features from voice video presence IM and others A federation service may also provide gateways to inter operate with other non SIP devices For example a SIP to Jabber gate way could interconnect the SIP federation with a Jabber federation A federation service authent
5. Compliments of i Avaya leader in IP innovations SIP Communications A Reference for th Rest of Us AA ee aN SIP Communications FOR DUMMIES AVAYA CUSTOM EDITION by Peter Gregory with Tom Doria Chris Stegh and Jim Su Foreword by Alan B Johnston WILEY WileySPatishing Inc SIP Communications For Dummies Avaya Custom Edition Published by Wiley Publishing Inc 111 River Street Hoboken NJ 07030 5774 www wiley com Copyright 2006 by Wiley Publishing Inc Indianapolis Indiana No part of this publication may be reproduced stored in a retrieval system or transmitted in any form or by any means electronic mechanical photocopying recording scanning or otherwise except as permitted under Sections 107 or 108 of the 1976 United States Copyright Act without the prior written permission of the Publisher Requests to the Publisher for permission should be addressed to the Legal Department Wiley Publishing Inc 10475 Crosspoint Blvd Indianapolis IN 46256 317 572 3447 fax 317 572 4355 or online at http www wiley com go permissions Trademarks Wiley the Wiley Publishing logo For Dummies the Dummies Man logo A Reference for the Rest of Us The Dummies Way Dummies Daily The Fun and Easy Way Dummies com and related trade dress are trademarks or registered trademarks of John Wiley amp Sons Inc and or its affiliates in the United States and other countries an
6. s structured language stands out so that IT people can understand and interpret it But if you need security you can simply encrypt this easy to read information Streamline your systems tige times and troubleshooting processes in no time Turn to Part 5 if you want to learn more BUSINESS CAREERS amp PERSONAL FINANCE Home Buying DUNMIES Grant Writing DUNMIES A Reterence fer the Rest of Ust A Reference fer the Rest of Us 0 7645 5307 0 Also available 1 Accounting For Dummies t 0 7645 5314 3 Business Plans Kit For Dummies t 0 7645 5365 8 Cover Letters For Dummies 0 7645 5224 4 Frugal Living For Dummies 0 7645 5403 4 0 7645 5331 3 t Leadership For Dummies 0 7645 5176 0 Managing For Dummies 0 7645 1771 6 HOME amp BUSINESS COMPUTER BASICS Excel 2003 Windows XP DUMMIES 0 7645 4074 2 0 7645 3758 X Also available 1 ACT 6 For Dummies 0 7645 2645 6 iLife 04 All in One Desk Reference For Dummies 0 7645 7347 0 iPAQ For Dummies 0 7645 6769 1 Mac OS X Panther Timesaving Techniques For Dummies 0 7645 5812 9 1 Macs For Dummies 0 7645 5656 8 Microsoft Money 2004 For Dummies 0 7645 4195 1 FOOD HOME GARDEN HOBBIES MUSIC amp PETS Feng Shui DUNMIES me u z i a A Reference for the Rest of Us A Referenca for the Rest of Us 0 7645 5295 3 0 7645 5232 5 INTERNET amp DIGITAL MEDIA Dig
7. disruptive events than are larger businesses For small businesses service and responsiveness are critical and the consequences for disruptive events are great Peer to Peer SIP Communications Overview In large enterprises SIP is most often implemented using cen tralized services such as proxy servers presence servers gateways and location servers But SIP endpoints can also function without all of these central services in small office settings those environments that can least afford the investment and maintenance required of these big company services A new simpler variant protocol of SIP called peer to peer P2P SIP promises a solution P2P SIP collapses some of the more complex server functions into the phones or other endpoints themselves P2P SIP relies on the core SIP philosophy that intelligence in communications solutions should reside in the endpoint refer to Part 2 for more about the variety of SIP endpoints available Contrast this approach with that of old fashioned analog telephones that did little more than amplify voice signals and rely upon intelligent switches to function SIP guide Part 6 SIP and Server Free Communications 5 The peer to peer layer effectively replaces the registration location and lookup steps of SIP It handles three things Registering a phone or a user with the peer to peer overlay network when the phone or user joins the network Y Looking up a phone or a user in
8. of parameters SIP guide 30 SIP Communications For Dummies Avaya Custom Edition By linking multiple modes of communication with user prefer ence SIP provides a unifying solution that helps to reduce user and operating costs by making even advanced com munications more intuitive and more consistent to the user Instead of requiring the user to interpret and interact with multiple applications interfaces and addresses the commu nication system adapts to the need of the user Catering to the Mobile User with SIP Because SIP enables a user to associate a single address with multiple communication devices communication types or User Agents UAs as discussed in Part 2 SIP natively enables mobility based communications Because an AOR can be associated with any number of devices and or phone numbers SIP can help your company leverage all kinds of mobile communication devices as part of a SIP enabled enterprise Applying the concepts of intelligent forking described earlier in the section Using Presence to Route Communications SIP can direct communications to any number of mobile UACs user aagent client devices including cell phones mobile IM devices such as BlackBerry devices and Treos and SIP softphones on laptops As with e mail addresses users probably won t memorize other users SIP AORs Instead they ll have address books and buddy lists just like they do on their e mail systems cell phones and IM
9. 5255 4 Scrapbooking For Dummies 0 7645 7208 3 Senior Dogs For Dummies 0 7645 5818 8 Singing For Dummies 0 7645 2475 5 30 Minute Meals For Dummies 0 7645 2589 1 Home Recording For Musicians For Dummies 0 7645 1634 5 The Internet For Dummies 0 7645 4173 0 iPod amp iTunes For Dummies 0 7645 7772 7 Preventing Identity Theft For Dummies 0 7645 7336 5 1 Pro Tools All in One Desk Reference For Dummies 0 7645 5714 9 Roxio Easy Media Creator For Dummies 0 7645 7131 1 id Available wherever books are sold For more information or to order direct U S cus tomers visit www dummies com or call 1 877 762 2974 U K customers visit www wileyeurope com or call 0800 243407 Canadian customers visit www wilev ca or call 1 800 567 4797 WILEY SPORTS FITNESS PARENTING RELIGION amp SPIRITUALITY Parenting DUNMIES Golf DUMMIES 0 7645 5146 9 0 7645 5418 2 TRAVEL Italy DUMMIES A Travet Guide for the Rent af Und 0 7645 5438 7 0 7645 5453 0 Also available Adoption For Dummies 0 7645 5488 3 1 Basketball For Dummies 0 7645 5248 1 The Bible For Dummies 0 7645 5296 1 1 Buddhism For Dummies 0 7645 5359 3 1 Catholicism For Dummies 0 7645 5391 7 Hockey For Dummies 0 7645 5228 7 Also available Alaska For Dummies 0 7645 1761 9 1 Arizona For Dummies 0 7645 6938 4 Cancun and the Yucatan For Dummies 0 7645 2437 2 Cruise Vacations For Dummies 0 7645 6941 4 1
10. 6943 0 1 Macromedia Flash MX 2004 For Dummies 0 7645 4358 X 1 Photoshop 7 All in One Desk Reference For Dummies 0 7645 1667 1 1 Photoshop cs Timesaving Techniques For Dummies 0 7645 6782 9 MPHP 5 For Dummies 0 7645 4166 8 PowerPoint 2003 For Dummies 0 7645 3908 6 QuarkXPress 6 For Dummies 0 7645 2593 X Network Security For Dummies 0 7645 1679 5 Networking For Dummies 0 7645 1677 9 TCP IP For Dummies 0 7645 1760 0 VBA For Dummies 0 7645 3989 2 Wireless All In One Desk Reference For Dummies 0 7645 7496 5 AWireless Home Networking For Dummies 0 7645 3910 8 o Integrate SIP with existing systems and simplify your communications architecture Explanations in plain English Get in get out information Icons and other navigational aids Top ten lists A dash of humor and fun ee Leverage SIP and Presence to streamline communications and eliminate phone tag Better support your mobile work force with SIP enabled communications Take advantage of SIP for PBX less communications Get smart www dummies com etips dummies com
11. Edition Creation of New Services SIP is a structured text based protocol that is modeled after HTTP or HyperText Transport Protocol the language that powers the World Wide Web SIP opens the door to a much larger developer community than traditional CTI and so offers your company the potential to create competitive advantages with intelligent communications Because SIP is based on HTTP application developers and system engineers will have an easier time developing and integrating applications into their communications environ ments Part 2 explains this more thoroughly Native Mobility As more devices become SIP capable users will be able to pick up and go at will but still communicate as if they were in their office Their presence and readiness to communicate will still be visible to their buddies For example SIP s awareness of a user s communication capa bilities will aid international travelers who have to use different cell phones and other messaging devices and protocols in dif ferent countries A caller trying to locate such a traveler need not know the traveler s availability or location SIP by nature will know how a person can be reached and facilitate the connection Take a trip to Part 3 to find out more Ease of Implementation and Support Because SIP is modeled after HTTP as a text based language it is easy to learn troubleshoot and support From analyzing network packets to application code SIP
12. Europe For Dummies 0 7645 5456 5 lreland For Dummies 0 7645 5455 7 GRAPHICS DESIGN amp WEB DEVELOPMENT PHP amp MySQL DUMMIES 0 7645 4345 8 0 7645 5589 8 Also available 1 Adobe Acrobat 6 PDF For Dummies 0 7645 3760 1 Building a Web Site For Dummies 0 7645 7144 3 1 Dreamweaver MX 2004 For Dummies 0 7645 4342 3 FrontPage 2003 For Dummies 0 7645 3882 9 1 HTML 4 For Dummies 0 7645 1995 6 1 Illustrator cs For Dummies 0 7645 4084 X NETWORKING SECURITY PROGRAMMING amp DATABASES C DUNMIES Hacking 0 7645 6852 3 0 7645 5784 X Also available 1 A Certification For Dummies 0 7645 4187 0 1 Access 2003 All in One Desk Reference For Dummies 0 7645 3988 4 Beginning Programming For Dummies 0 7645 4997 9 YC For Dummies 0 7645 7 0684 uide 1 Firewalls For Dummies 0 7645 4048 3 Home Networking For Dummies 0 7645 42796 Judaism For Dummies 0 7645 5299 6 Martial Arts For Dummies 0 7645 5358 5 Pilates For Dummies 0 7645 5397 6 Religion For Dummies 0 7645 5264 3 Teaching Kids to Read For Dummies 0 7645 4043 2 Weight Training For Dummies 0 7645 5168 X Yoga For Dummies 0 7645 5117 5 Las Vegas For Dummies 0 7645 5448 4 1 London For Dummies 0 7645 4277 X New York City For Dummies 0 7645 6945 7 Paris For Dummies 0 7645 5494 8 RV Vacations For Dummies 0 7645 5443 3 Walt Disney World amp Orlando For Dummies 0 7645
13. Registrar authenticates and registers users when they come online and then stores information on the users logical identities and the devices that they can use for communications The devices are identified by their URIs 1 Location Service As users roam the network needs to be continually aware of their locations The location service is a database that keeps track of users and their locations The location service gets its input from the registrar server and provides key information to the proxy and redirect servers A SIP proxy or redirect server uses this information to obtain the mapping from logical SIP addresses to physical SIP addresses so that communication sessions can be properly established and maintained SIP guide 20 SIP Communications For Dummies Avaya Custom Edition Redirect Server If users are not in their home domains sessions bound for them needs to be redirected to them The redirect server maps a SIP request destined for a user to the URL of the device closest to the user For example if a call is destined for ei leendover company com and the user is on the road the com pany s redirect server may reply to the caller s user agent or to the requesting proxy server with the contact address of the user s cell phone so that the incoming call can be redirected to the cell phone 1 Proxy Server A proxy server takes SIP requests processes them and passes them downstream while sending
14. and tear down Q calls Although SIP s role is expanding and it now does things for which it wasn t initially intended it needs help from other standards when it comes to SIP guide Part 5 SIP Interoperability 4 7 1 Interoperability among IVRs Firewalls Y Conferencing bridges Instant messaging platforms In essence these systems must rely on much more than stan dard SIP to make them work together Nevertheless SIP offers new options for multi vendor inte gration within an IP telephony environment based on open standards First when needed a specific user agent a client device such as a PDA phone can be connected to the PBX through SIP Next through federation services you can support basic connectivity between different vendors PBX systems using SIP Soon SIP will enable enterprises to combine multi ple PBXs into a single system which reduces complexity for both users and administrators SIP guide 48 SIP Communications For Dummies Avaya Custom Edition SIP guide Part 6 SIP and Server Free Communications In This Part Implementing SIP communications for small offices Getting the big picture on peer to peer communications Using peer to peer SIP for maximum benefits De SIP in the smallest business settings presents unique challenges Models for deploying and operating SIP in larger enterprises distributed or not may not be optimal for smaller businesses In this part we discuss some of
15. being held hostage by their communication devices you can find out more in Part 3 An Open Standard The SIP standard is defined in RFC 3261 by the Internet Engineering Task Force ETF The IETF is a large open international community of network designers operators vendors and researchers including Avaya who are all con cerned with the evolution of the Internet architecture and the smooth operation of the Internet As a result enterprises have choices for their platforms devices and applications Want to discover more Turn to Part 2 Interoperability Several working groups including SIPit SIP Foundry and SIP Forum arrange events where companies with SIP hardware and software products can test interoperability with other SIP products This process helps to promote smoother inte gration of SIP products in enterprise networks SIP s ability to work across a range of systems helps enter prises enjoy more seamless integrations between platforms devices and applications so your company can get more done with less CTI an Ma programming Part 5 is the place to go for more informa Part 8 Top Ten Reasons for SIP Enhanced Communications 63 Unified Addressing A single SIP AOR address of record provides a unifying iden tifier that can be used for routing all communication to a user Simply put an AOR allows for a single user identity to be mapped across multiple devices so that people connect with people without
16. clients today A SIP AOR will be just another data field associated with each person or group When used by a SIP device the URI will be retrieved and used to start communicating with another party Initial efforts to develop SIP enabled converged seamless mobility solutions might appear to be aimed mainly at wire less voice calls within wireless networks to lower usage charges and require fewer phones For example Avaya and its partners have pioneered the development of multimode SIP phones with both cellular and Wi Fi antennae Although SIP guide Part 3 How SIP Transforms User Communications 3 a company can certainly gain cost savings and other effi ciencies the real benefit is that these efforts also serve as a steppingstone towards next generation communications applications powered by SIP Consider a business communications solution where SIP is the common interface providing integration between enter prise networks and service provider networks While roaming in a service provider network users can stay in touch with their virtual enterprise anywhere anytime any place as though they had never left the premises Users in such an environment can instantly receive enterprise voice message notifications while out of the office Users such as doctors who work across multiple loca tions don t have to carry yet another phone pager or PDA 1 Services support improves because service manage ment can loc
17. how SIP prom ises to revolutionize electronic communications How This Book Is Organized Each part of this book considers a different aspect of SIP envi ronments You may want to read the book cover to cover to gain a fuller understanding of SIP or you may prefer to skip around to find out what you need when you need it Part I The Case for SIP gives you the high level view of what SIP is and what it can do for your company s communica tions If you re unfamiliar with SIP s benefits this is a great place to begin Part II SIP at a Glance explains how being based in current standards makes SIP compatible with existing systems It also introduces presence the SIP feature that adds intelligence to communications at many levels and it describes the compo nents in a SIP network that make intelligent communications possible SIP guide Introduction Part III How SIP Transforms User Communications describes how SIP addressing works with the concept of presence to make reaching users easier regardless of which device they re using or where they are Part IV How SIP Transforms Enterprise Communications explains how SIP drives down the cost and complexity of intra enterprise and inter enterprise communications by permitting their consolidation with IP data communications This part delves into the details of basic SIP calls including proxy mediated voice calls presence enabled calls instant messaging and videoco
18. indicating its ability to communicate Presence distributes the following information 1 User status that is online or offline Y User availability such as available busy on the phone or out to lunch 1 User s desired c amp iftgutdmeans such as instant messag ing desk phone cell phone pager and so on 24 SIP Communications For Dummies Avaya Custom Edition Probably the earliest manifestation of presence is the tele phone network s busy signal signaling to a caller that the party is unable to communicate right now because he or she is already communicating with someone else Instant messaging has taken presence a step further with states that include Available Away On the Phone and Busy plus customizable preferences that include any mes sage that the user wants to share see Figure 3 1 But unlike IM s customizable states SIP s presence states are generally predefined which permits predictable routing decisions to be made based upon a user s specific presence oS v Dashboard S72 ot A F 0a fy Erernareornoroer E Z3 2 o mcr LAIRD gt Communications gt History v Contacts Online Offline Online On the phone Figure 3 1 Enterprise presence and buddy list geben Presence doesn t just apply to people and need not apply to s just one entity it can also be associated with a device or a group For example a presence status might capture the status of a device P
19. needing to know which devices they have and are presently using This address eliminates the need for tracking users multiple phone numbers e mail addresses and IM contact names Turn to Part 3 for the scoop on AOR Operational Cost Savings SIP trunks are IP trunks from service providers that use SIP for call control and routing enabling enterprises to create a single pure IP connection to carrier clouds Voice traverses the network just like other IP applications SIP trunks reduce operational costs by enabling the enter prise to eliminate hardware software and recurring network charges associated with using traditional PSTN trunks for voice communications If you re keen on cutting costs you can find out more in Part 4 Simplified Communications Architecture At the foundation of SIP s philosophy is the concept that intel ligence should reside in the endpoint This concept is evident in SIP s native ability to support peer to peer communications Peer to peer environments don t rely on communications servers gateways or other intermediate devices to support communications between users Peer to peer SIP networks are easy to set up and administer yet can include features such as automated attendant voice mail and three party conferencing This architecture is best exemplified by Avay spQuid amp Edition solutions We explain this in detail in Parts 4 and 6 64 SIP Communications For Dummies Avaya Custom
20. on our other products and services please contact our Customer Care Department within the U S at 800 762 2974 outside the U S at 317 572 3993 or fax 317 572 4002 For technical support please visit www wiley com techsupport Wiley also publishes its books in a variety of electronic formats Some content that appears in print may not be available in electronic books ISBN 13 978 0 470 04149 9 ISBN 10 0 470 04149 8 Manufactured in the United States of America 100987654321 10 QT QU QW IN SIP guide WILEY Publisher s Acknowledgments We re proud of this book please send us your comments through our online registra tion form located at www dummies com register For details about how to create a For Dummies book for your company or organization please contact dummiesrights amp licenses wiley com Some of the people who helped bring this book to market include the following Acquisitions Editorial and Composition Services Media Development Project Coordinator Kristie Rees Project Editor Jan Withers Layout and Graphics Business Development Representative Stephanie D Jumper Heather Ryan Jackie Smith Proofreader Amanda Briggs Editorial Manager Rev Mengle Special Help Millicent Barksdale Cartoons Rich Tennant Jennifer Bingham Lisa Kluberspies www the5thwave com Gabriele McCann Publishing and Editorial for Technology Dummies Richard Swadley Vice President and Executive Group Publisher Andy Cummings Vi
21. out and reconnect the current tangle of disparate communi cations protocols and programs Yes To understand the power behind this protocol you need to examine some of the St factors that are driving SIP s momen tum across all aspects UF GH t prise communications Part 1 The Case for SIP A brief history of SIP SIP traces its origins to the mid 1990s The original draft of the SIP specifica in the Internet s experimental multicast tion was published in the IETF in 1996 backbone or Mbone This network and eventually standardized in 1999 was used to facilitate the distribution of Today the most up to date core SIP streaming multimedia contentinclud specification can be found in RFC ing seminars broadcasts of space Request for Comment 3261 shuttle launches and IETF meetings Presenting Presence Services SIP introduces a new model for communications through its support of presence Presence enables you to locate a user and determine his willingness and ability to participate in a session even before you initiate communications This infor mation reflected across multiple devices such as IP phones cell phones and instant messaging clients makes communi cation simple and efficient by helping you to reach the right person at the right time on the right device Presence and preference features enabled by SIP are dis cussed in more detail in Part 3 Celebrating User Centric Communications Communicati
22. responses upstream to other SIP servers or devices A proxy server may act as both a server and a client and can modify a SIP request before passing it along A proxy is involved only in the setup and tear down of a communication session After user agents establish a session communications occur directly between the parties 1 Presence Server In order for users to see the presence of their buddies to improve communication they often refer to a presence server Presence servers accept store and distribute presence information The pres ence server has two distinct sets of clients e Presentities producers of information provide presence information about themselves to the server to be stored and distributed e Watchers consumers of information receive presence information from the server Watchers can subscribe to certain users much like IM users choose which buddies to add to their list Now you may be saying to yourself whew that s a lot of servers However these functions are usually embedded in a single appliance such as Avaya s SIP Enablement Services platform which also supports standards based instant messaging SIP guide Part 2 SIP at a Glance 2 Basic SIP Operations This section walks you through a basic communication session how it works and how SIP supports it Figure 2 2 illustrates the path of a typical session D Mi
23. short are devices that sit at the edge of a SIP enterprise network and a carrier or ISP network cloud Among the multiple functions these devices can provide some SBCs have been designed to sup port both inward and outward translation of URIs to E 164 phone number addressing A simplified communications Architecture Enterprises can benefit from the simplification of enterprise networks through the standardization on SIP this is true for both internal and external communications As SIP becomes ubiquitous in both service provider and enterprise networks it introduces a single standard interface for all con nectivity whether for adding endpoints deploying contact center adjunct services or even connecting trunk services for external communications Proprietary signaling protocols and hardware intensive digital analog interfaces give way toa simple logical SIP interface that connects application servers residing on industry standard platforms With SIP as a unifying protocol you can dramatically reduce the need for dedicated hardware gateways and devices Variants of voice centric T1 and E1 standards will begin to diminish as SIP globally stan dardizes the interface SIP guide 38 SIP Communications For Dummies Avaya Custom Edition gore In a converged network voice becomes an IP application sharing the common network infrastructure and services Connecting SIP Enterprises A common concern for companies contempl
24. store and distribute contact lists access control lists for user presence and device parameters such as speed dials and fea ture button mappings to the active SIP endpoint being used A Web based interface the SIP Personal Information Manager enables users to securely manage and view their profile and device information using any standard Web browser The user simply logs in through the endpoint after the user is authenti cated his stored data is securely downloaded into the device to create a customized user environment Keeping pace with the mobile user SIP enables seamless mobile communications anytime anywhere For example suppose a bank executive adds a new contact to her personal profile and assigns it a hot button or speed dial She then initiates a SIP call through the internal network using her dual mode cell phone to check voice mail While still listening to messages she walks out of the office to her car and the call switches on the fly to her cellular service provider network She then arrives at headquarters still on the cell phone The intelligent network using SIP detects her presence and switches the call back to the company s wireless network automatically The executive then finds a mobile user cubi cle with a PC and softphone application upon authentication her entire contact listand phone features are downloaded She then checks her buddy list sees via presence that her new co
25. style addresses formatted con tact addressing the public switched telephone network PSTN and the Internet can be seamlessly linked together With SIP users can potentially contact any user whether they are on the PSTN or on the Internet Enabling Voice Video and IM Oh My In keeping with the IETF philosophy of defining simple proto cols with powerful functionality SIP follows a peer to peer architecture containing a small set of different methods types of messages At the same time SIP is also very modu lar and extensible enabling you to integrate SIP into your existing legacy communications environment As a result SIP can interoperate with many traditional telephony protocols and scenarios as well as with emerging communications serv ices These properties make SIP an ideal protocol for any company implementing a standards based converged com munications network SIP is not designed simply to replace the PSTN Rather SIP goes well beyond traditional telephony by facilitating any type of peer to peer communication session instant messag ing video gaming conferencing and collaboration SIP is also not designed to be a one stop shop for protocol needs You essentially use SIP to set up and tear down media sessions for example IM text voice or video communica tion sessions SIP combines with other network protocols as well as application layer technologies to provide complete end to end functionality One suc
26. those that work with Voice over Internet Protocol VoIP Here s a short list of the kinds of products you can expect to become SIP enabled 1 VoIP phones gateways proxies and servers 1 VoIP softphones phone software programs that run on PCs PDAs and other devices 1 VoIP PBXs Instant messaging IM programs 1 Videoconferencing systems SIP is an open standard with an active working group on the Internet Engineering Task Force IETF that has given SIP tremendous legitimacy and momentum Avaya and other major companies aregyctjyigdn the IETF SIP working group as 2 SIP Communications For Dummies Avaya Custom Edition well as in other industry groups working to make sure that SIP works across enterprises that have a variety of architec tures standards and products in use About This Book This book describes SIP from both business and technical perspectives You can read about SIP architecture and opera tions as well as its impact on business You can discover how SIP can improve internal and external communications as well as the basics of how SIP technology works and how to build a SIP environment Foolish Assumptions We assume that you have a keen interest in ensuring that your company s networking and telecommunications systems are up to the challenges of intelligent communications today and tomorrow Regardless of your role in your organization this book can help you quickly get up to speed on
27. to communicate Getting Down to One Address for Everything One key feature of SIP is its ability to use an end user s address of record AOR as a single unifying public address for all communications So in the world of SIP enhanced communi cations a user s AOR becomes her single address that links the user to all of the communication devices or services that she uses For example diser Fileen Dover s AOR would look like A guide SIP eileendover company com Using this AOR a caller Part 2 SIP at a Glance 15 can reach Ejleen s multiple communication devices known as user agents or UAs to techno types without having to know each of Eileen s unique device addresses or phone numbers To complement the AOR SIP provides a mechanism called the Uniform Resource Identifier URI that establishes a common addressing scheme for all of an individual s user agents The format of a URI address follows the same basic format as a Web or e mail address contact address domain By applying this style of addressing SIP can map the unique addresses of a user s multiple devices and services to a com munication domain and then link all the user agents to a user s single AOR for that domain Following are some exam ples of how this URI might be applied Y A phone sip 408 555 1212 company com user phone A fax sip 408 555 1214 company com user fax 1 An IM user sip eileendover company com MBER we g
28. 2 In amp explains more about AORs Simply put SIP based communications are between people connected together without needing to know which device they happen to be using No more tracking of multiple phone numbers e mail addresses and IM contact names SIP is particularly suited to facilitating communications with mobile devices such as laptop computers cell phones and PDAs Part 3 describes how SIP enables mobile communications Nevertheless SIP still supports the legacy public switched telephone network PSTN with its numeric dialing because it s going to be around for quite a long time An effort to map PSTN telephone numbers with SIP s newer user centric iden tifiers is discussed in Part 4 SIP guide An Part 1 The Case for SIP Encouraging Interoperability seh s TUg SIP uses a text based language That doesn t mean that SIP supports only text it means that SIP s messages are easy to program and interpret making it easier to achieve interoper ability between different vendor implementations SIP is also very modular and extensible allowing for the integration of existing legacy protocols These properties make SIP an ideal protocol for implementing a standards based converged com munications network The SIP standard is defined in RFC 3261 by the Internet Engineering Task Force ETF The IETF is a large open international community of network designers operators vendors and res
29. al communications See Part 4 for more details on trunking with SIP An equally important foundation of SIP is the concept of distributed intelligence This concept evident in exciting new peer to peer P2P architectures such as Avaya one X Quick Edition creates a new paradigm in communications requir ing no PBX or communication server only intelligent phones and other endpoint devices as the mechanism for establish ing a working communications system We discuss Quick Edition in more detail in Part 6 SIP scales well for the smallest businesses where SIP enabled endpoints can be established in the absence of centralized proxies and registrars We discuss how SIP can power small offices in Part 6 Part 1 The Case for SIP Building a Foundation for Standardized Intelligent Communications SIP defined in IETF standards is a structured text based pro tocol that is modeled after HTTP or HyperText Transport Protocol the language that powers the World Wide Web Because SIP is text based and similar to HTTP application developers and system engineers will have an easier time developing and integrating applications with communica tions systems SIP s architecture consists primarily of SIP endpoints and SIP servers Endpoints are also called user agents the pro grams and devices that actually perform the communications between end users In small organizations the user agents can be smart enough to communicate to on
30. aries DLLs in Windows will contain function calls that know how to query presence servers and return rich and meaningful results Here s an example A factory assembly line worker is viewing the parts needed for an upcoming order in an inventory pro gram and notes that there is a shortage He can immediately view the presence of the line manager and procurement man ager of his own company and possibly even that of the parts supplier from within the inventory management application itself Using this data the worker can communicate status to the individual who is most likely to be able to act quickly Integration with Business Applications Taking the scenario described in the previous section Presence Enabled Business Applications a step further SIP will enable the line worker to click to conference with all contacts that are present firing up a collaborative conference call to discuss the inventory problem Open Web services will even allow the inventory application itself to check the pres ence of all relevant contacts and interact with a SIP enabled audio bridge to proactively out call to the parties removing the need for a human to start the process In fact each partici pant will have mini applications that provide a view into the part of the application being discussed operating within his conference calling software These mini applications will provide views back into the inventory application permitting
31. ate field technicians within a customer location very quickly and provide better service to cus tomers vy Administrative assistants can use presence to quickly locate their staff members to get attention to a matter that requires immediate action 1 SIP enabled user devices can respond to a phone call by responding with a short IM that lets the caller know about the person s availability x SIP is well suited for mobile environments SIP s registration function is similar to that in cell networks When a user turns 7 on a SIP device it registers the user and sends the device s URI to the registrar server which routes calls to and from the user This system ties together multiple communication silos for example e mail IM desk phone cell phone and so on using a single address that can reach the user regardless of location Native mobility is one of the reasons that the Third Generation Partnership Project 3GPP which is defining specifications for third generation 3G mobile systems has adopted SIP as the primary signaling protocol TECH Sl SIP guide 32 SIP Communications For Dummies Avaya Custom Edition What about the user s highly personalized services such as address lists buddy lists and speed dials SIP preference tools features can make these personal services mobile For exam ple Avaya s Personal Profile Manager provides a centralized service that communicates with SIP endpoints to receive
32. ating the switch to SIP is how quickly all these nifty advances are going to come together in a truly comprehensive way In particular how can isolated enterprises exchange directory information Sure each step toward SIP is a step in the right direction but how do you get everyone marching in step The SIP world calls reaching that higher level of inter connectedness federating In recent years businesses have enthusiatically adopted IP for their intracompany communications For example today more IP PBXs are sold than conventional TDM PBXs However today most of these IP communications tools stop at the enterprise boundary IP PBXs fall back to TDM and revert to phone calls for communication outside of the enter prise As a result islands of IP communication are growing but they are not interconnected As SIP has matured as a standard the interconnection of these islands over the Internet has become a technical possibility The benefits of such interconnection are enormous For instance you can 1 Extend enhanced services beyond the enterprise boundary Make available additional modes of communication including multimedia presence and IM Enjoy higher quality connections Reduce costs by bypassing TDM network interconnections If two enterprises both have SIP they can interconnect and enable SIP to SIP calling Beyond calling they can now interact via multimedia sessions presence and instant messaging
33. ations can then reference entries stored in LDAP structures to resolve and translate phone numbers to URIs Vendors are already expressing support for LDAP intercon nectivity For example with a simple plug in Avaya s SIP Enablement Services platform can interface with LDAP to send calls bound for SIP URIs to standard telephones on the enterprise s IP PBX SIP guide 42 SIP Communications For Dummies Avaya Custom Edition SIP guide Part 5 SIP Interoperability In This Part Getting greater interoperability within a company Examining interoperability between companies Looking at industry interoperability efforts Integrating multiple vendors Ss is successful and widespread because it is open extensible and driven by the IETF Great strides have already been made to make SIP interoperable among the growing community of SIP enabled hardware and software products In this part we discuss interoperability from the perspectives of operating within enterprises and among enterprises Internal to the Enterprise SIP is the most interoperable multimedia signaling protocol to date SIP has approximately 20 standard features that func tion admirably across multiple vendors equipment as tested periodically at S Pit and InteropNet Labs iLabs events Avaya and other vendors actively test interoperability of their SIP services and endpoints at these events further advancing the openness of their solutions try Although SIP
34. blement Services to provide a networked solution for enterprises with distributed small offices Essentially this solution uses SIP routing capabilities to efficiently connect distant loca tions that have peer to peer SIP SIP guide 54 SIP Communications For Dummies Avaya Custom Edition SIP guide Part 7 SIP and the Future of Intelligent Communications In This Part Increasing business applications productivity with presence Improving the ease and speed of multimodal communications Becoming smarter about prioritizing messages Roaming around with location aware services Maintaining privacy Enabling new services Ec write this part we got out our crystal ball and polished it up a bit waved a cell phone over it and chanted Presence Presence Presence PRESENCE Then we just typed what appeared Presence Enabled Business Applications Combined with Web services and XML based applications SIP will enable presence within business applications Desktop programs that have references to business contacts within them will be enabled to show the presence of those contacts on the screen within that application You won t need to toggle to an IM client to view the presence of the contact SIP guide 56 SIP Communications For Dummies Avaya Custom Edition Reus Applications will not need to be customized to account for s AOS new SIP capabilities Rather common libraries such as Y V7 dynamic linked libr
35. can also apply to a group of users for example Finance Group or a device for example Phone Status Off hook or On hook Even more exciting both users and applications can access presence information providing the opportunity to create next generation converged communication applications For example your network can deliver new capabilities such as polite calling calls that are less disruptive for the party being called as when based on information from her calendar application calls to an executive can automatically be routed to an assistant if the executive is scheduled to be in a meeting Components in a SIP Network When you are ready to enhance your communications with SIP it s important to understand the building blocks that you will need to form the foundation of your new SIP enhanced enterprise SIP guide 18 SIP Communications For Dummies Avaya Custom Edition Agents and Servers These components can take the form of an additional software program on a laptop computer for example or as an inherent part of a mobile device such as a PDA or cell phone Using user agents User agents UAs are applications in SIP endpoints such as a SIP phone cell phone PDA or workstation as shown in Figure 2 1 that interface between the user and the SIP network A user agent can act as either a client or a server When sending SIP messages the UA acts as a user agent client UAC and when receiving m
36. ce President and Publisher Mary Bednarek Executive Acquisitions Director Mary C Corder Editorial Director Publishing for Consumer Dummies Diane Graves Steele Vice President and Publisher Joyce Pepple Acquisitions Director Composition Services Gerry Fahey Vice President of Production Services Debbie Stailey Director of Composition Services SIP guide Contents at a Glance Foreword aiea ees ese in eds V Initod ctioi sinnn 1 Part 1 The Case for IPeccccccccccccsccesccc 5 Part 2 SIP at a Glance 13 Part 3 How SIP Transforms User Communications sssessessssssssssssssssssssssasasaaaaaaaas 23 Part 4 How SIP Transforms Enterprise COMMUNICATIONS oiccccccsssscccccscenseccceenecaeeeeeeeeaees 33 Part 5 SIP Interoperability essc 43 Part 6 SIP and Server Free Communications 49 Part 7 SIP and the Future of Intelligent Communications 1 cccccscccseseess 55 Part 8 Top Ten Reasons for SIP Enhanced COMMUNICATIONS 6 cccccceeccecceceeceeeeeeeeceaeeeeneees 61 SIP guide Foreword hese days in communications circles Session Initiation Protocol or SIP for short is seemingly everywhere SIP is supported by practically every manufacturer of IP Phone Gateway Call Manager and IP PBX It is part of the IP Multimedia Subsystem IMS It is powering the fastest growing VolP resi dential and enterprise providers It is a part of PC operating systems and has been enthusiastically adopted by the open source movement Y
37. chael s Proxy John s softphone server SIP phone INVITE F1 a INVITE F2 100 Trying F3 a 100 Trying F4 180 Ringing F5 180 Ringing F6 200 OK F7 200 OK F8 ACK F9 gt Media Session lt gt BYE F10 lt 200 OK F11 gt Figure 2 2 A typical SIP session s ladder diagram The scenario in Figure 2 2 shows two users Michael smallcompany com and John bigcompany com using SIP user agents calling point to point through a proxy server Examples of UAs could be an Avaya SIP Phone a SIP softphone or a PDA phone The proxy server works to connect the two UAs The communication then follows these steps 1 Michael smallcompany com the UAC initiates a session by inviting John bigcompany com SIP guide 22 SIP Communications For Dummies Avaya Custom Edition 10 11 An INVITE request is generated and sent to John The INVITE message contains Session Description Protocol SDP parameters that define the types of media the caller can accept and where it wishes the media to be sent A DNS SRV record lookup for SIP services resolves to John s proxy server proxy bigcompany com The INVITE request is sent to the proxy server The server receives and processes the invitation and looks up Michael s contact in the Registrar The Registrar returns host officephone bigcompany com where John is currently located The proxy server generates and sends an INVITE request to the server host
38. change how you make connections to telco carriers SIP trunks offer a number of benefits including PSTN origination termination Many SIP service providers support origination termination services directly to the PSTN from their SIP networks This practice enables the enterprise to reduce the monthly recurring costs associated with multiple TDM circuits by deploying a single IP pipe to the service provider network DID and 800 Number Mobility These features take advantage of the fact that SIP is geographically agnostic They allow calls destined to a local or 800 number to be SIP guide _ ____ Part 4 How SIP Transforms Enterprise Communications 3 7 AL S TUp FY 2 1 Od 48 automatically rerouted over the service provider SIP network to another enterprise location For enterprises this system offers great flexibility in providing a local presence in all their markets while routing calls to a centralized call center for more efficient service Cost savings For enterprises SIP networking means reducing the monthly recurring cost of separate PSTN and data circuits to the premises When you remove voice circuits you reduce the number of TDM T1 inter faces on the IP PBX because hundreds of VoIP calls can come from the same hardware footprint as a single T1 interface Service providers may also offer reduced toll charges to customers when SIP is used as the interface to the PSTN Session Border Controllers SBCs for
39. ctionality gaps Although the consumer industry has made some efforts to address these problems with small scale Enterprise IM solutions scalability and business continuity issues remain A SIP based open standards implementation of IM enables interdomain IM via an IM gateway that routes messages to other popular public domain IM services even those that are external to the enterprise Additionally SIP also enables the possibility of sendi MNs to next generation cell phones and Wi Fi devices via a Service Provider Gateway 28 SIP Communications For Dummies Avaya Custom Edition x Tu Because SIP can determine through the Session Description RY fis Protocol SDP what type of media stream the answering UA mY 7 can support SIP can make intelligent choices on what type of modality to use Part 2 explains more about SIP and SDP However IM is just the beginning SIP has the unique and nat ural ability to support multiple media types within a single communication session This broad support creates a natural solution for providing communications that adapt to the user based on his or her situation and communication device being used s s The term multimodality refers to the ability for a user or RY OO device or application to communicate through more than g 7 one mechanism For example a user may be able to input text via voice or typing on a keyboard An application such as the Avaya SIP Softphone may be able to delive
40. d may not be used without written permission All other trademarks are the property of their respective owners Wiley Publishing Inc is not asso ciated with any product or vendor mentioned in this book LIMIT OF LIABILITY DISCLAIMER OF WARRANTY THE PUBLISHER AND THE AUTHOR MAKE NO REPRESENTATIONS OR WARRANTIES WITH RESPECT TO THE ACCURACY OR COMPLETE NESS OF THE CONTENTS OF THIS WORK AND SPECIFICALLY DISCLAIM ALL WARRANTIES INCLUDING WITHOUT LIMITATION WARRANTIES OF FITNESS FOR A PARTICULAR PURPOSE NO WARRANTY MAY BE CREATED OR EXTENDED BY SALES OR PROMOTIONAL MATERIALS THE ADVICE AND STRATEGIES CONTAINED HEREIN MAY NOT BE SUITABLE FOR EVERY SITU ATION THIS WORK IS SOLD WITH THE UNDERSTANDING THAT THE PUBLISHER IS NOT ENGAGED IN RENDERING LEGAL ACCOUNTING OR OTHER PROFESSIONAL SERVICES IF PRO FESSIONAL ASSISTANCE IS REQUIRED THE SERVICES OF A COMPETENT PROFESSIONAL PERSON SHOULD BE SOUGHT NEITHER THE PUBLISHER NOR THE AUTHOR SHALL BE LIABLE FOR DAMAGES ARISING HEREFROM THE FACT THAT AN ORGANIZATION OR WEBSITE IS REFERRED TO IN THIS WORK AS A CITATION AND OR A POTENTIAL SOURCE OF FURTHER INFORMATION DOES NOT MEAN THAT THE AUTHOR OR THE PUBLISHER ENDORSES THE INFORMATION THE ORGANIZATION OR WEBSITE MAY PROVIDE OR RECOMMENDATIONS IT MAY MAKE FURTHER READERS SHOULD BE AWARE THAT INTERNET WEBSITES LISTED IN THIS WORK MAY HAVE CHANGED OR DISAPPEARED BETWEEN WHEN THIS WORK WAS WRIT TEN AND WHEN IT IS READ For general information
41. e another without the need for servers In large enterprises centralized SIP servers such as proxies registrars and presence servers facilitate user agent communications SIP components and even an example call scenario are found in Part 2 SIMPLE SIP for Instant Messaging and Presence Leveraging Extensions is an important standard that facilitates instant messaging communication SIMPLE is essentially a standardi zation of SIP s presence features We describe SIMPLE in more detail in Part 2 Where Will SIP Take Communications in the Future SIP extensible and versatile as it is continues to grow and evolve In the near future you ll likely see SIP become inte grated into business applications with several types of functionality far beyond simple click to call hyperlinks Applications will be able to make communications routing and other decisions ba8ediaypon interaction with users 2 SIP Communications For Dummies Avaya Custom Edition We re predicting that the multiple addresses associated with various modes of communication IM text messaging e mail phone will collapse into a single SIP user id This single user id coupled with SIP presence servers will put communica tions with the right people and in the right medium at your fingertips no matter what kind of communications device you or they are currently connected to SIP may also follow the lead of E911 emergency location serv ices in cellula
42. earchers concerned with the evolution of the Internet architecture and its operation Several neutral consortiums including SIPit SIP Foundry and SIP Forum arrange meetings and events where companies with SIP based hardware and software products can test interoperability with other SIP based products This testing helps to promote smoother integration of SIP based products in carrier and enterprise networks We tackle this subject in depth in Part 5 Some vendors have gone beyond these efforts with active SIP interoperability and ecosystem programs In a well run SIP ecosystem devices and services obviously need to work together seamlessly and the only way to ensure that they do is for many kinds of vendors to test their SIP based products together For example Avaya has made a commitment to establishing openness and interoperability for SIP through its Developer Connection program which support software developers systems integrators and service providers in testing interoperability and developing SIP based solutions with Avaya products and services You can find more infor mation about interoperability efforts in Part 5 The impact of SIP goes beyond internal communications within an enterprise SIP has become a signaling standard for carrier networks Service providers have started to provide SIP based trunk services that can reduce costs and extend an enterprise s SIP environment into the public network The adoption of SIP for e
43. ears ago someone proposed a usage of SIP that was dubbed SIP for Light Bulbs Don t laugh it may happen yet So what is SIP and why is the industry buzzing about it This book will tell you What can you use SIP for This book will tell you that too Why is SIP so important You ll find that here too Before I leave you in the competent hands of the authors I will add a few of my own answers here SIP can be called a rendezvous protocol That is it allows endpoints on the Internet to discover locate negotiate and establish sessions What kind of sessions Any kind of sessions SIP is used to establish VoIP of course video gaming text call control and others I m sure I ve left out Recent extensions to SIP add in instant messaging and presence capability What is pres ence This book will tell you but presence stands ready to revolutionize enterprise communications the same way public Instant Messenger networks have revolutionized con sumer communications Besides all these applications and uses SIP is also generating its own ecosystem In the same way that the Internet opened up networking by displacing closed proprietary networking protocols SIP has opened up communications and displaced closed and proprietary signaling protocols It has created an entire ecosystem of interoperable and configurable devices and services that is revolutionizing the way communications is done SIP guide Not bad for a l
44. er centric This part outlines how SIP is one innovative technology that actually helps improve communications without complicat ing these issues What Is SIP Session Initiation Protocol SIP pronounced just like sip as in sipping from a fire hose on a hot day is an open signaling protocol for establishing any kind of real time communication session The communication session can involve voice video or instant messaging and can take place on one of many devices that people use for communicating laptop computer PDA cell phone IM client IP phone and so on SIP has been developed in the nternet Engineering Task Force IETF by common participation from various vendors including Avaya SIP builds on a number of existing communications proto cols Developers and system administrators can easily work with SIP customize it and program with it It is rapidly becoming a standard for service integration how new serv ices and applications are created and combined within a variety of wireless and carrier networks and is gaining momentum within enterprises This growing acceptance in both enterprise and service provider networks offers the promise of a single unifying protocol that will transform not only communications within an enterprise but communica tions between the enterprise and its ecosystem of partners suppliers and customers Is SIP a refreshing solution to sim plifying communications For companies who need to sort
45. essages it acts as a user agent server UAS A back to back user agent B2BUA is an applica tion that acts as an intermediary between two parties but appears as an endpoint to both parties like a middleman It serves as both UAS and UAC simultaneously to process ses sion requests Instant Messaging Dual Mode dude dummies com Mobile Phone Softphone SIP Phone Figure 2 1 Some typical SIP user agents SIP guide TEC 59 ASTO a Part 2 SIP at a Glance 1 9 SIP devices can communicate directly if they know each other s URI or IP address but in practice SIP servers are often used in the network to provide an infrastructure for routing registration and authentication authorization services IP based devices can identify and communicate with one another using IP addressing alone However in most cases your network uses the Domain Name Service DNS to establish sessions with device names which DNS trans lates into IP addresses Similarly SIP devices frequently consult directory servers often by name which provide endpoint addresses that the devices then contact to set up a call Serving up SIP servers SIP servers provide centralized information and enablement services in a SIP ecosystem The core SIP servers and their functions are summarized here Registrar Server When users come online they need to make sure that others are aware that they re available to take and make calls The
46. fication of standard methods for negotiating pro tocols protocol extensions and exchanging capability information between endpoints Y Definition of authentication methods to ensure user security and accurate billing SIP vendors are tackling these interoperability issues now so that you won t have to face them on your own especially should your company adopt SIP technology in the near future Several groups are actively working on SIP interoperability including the following YY Developer Connection is Avaya s program that promotes interoperability between Avaya products and others in the market Go to http devconnectprogram com 1 iLabs InteropNet Labs engineers test the interoperabil ity of hundreds of commercial and open source prod ucts The 2005 SIP iLabs is designed to show the state of vendor interoperability using SIP You can read more at http www networkworld com research 2005 050205 ilabs sip html SipCenter promotes the development of SIP based products and interoperability Info can be found at http www sipcenter com 1 SIP Connect morphed into the SIP Forum as the IP PBX and Service Provider Interoperability Task Group Information is available from http www sipforum com 46 SIP Communications For Dummies Avaya Custom Edition SIP Foundry promotes interoperability of SIP prod ucts More information can be found at http sip foundry org SIPit SIP Interoperability Tes
47. ft a message for saying I m off the phone now can you call me back Or have you left a greeting on your work voice mail saying If you ve missed me you can call me on my cell phone or better yet send me an e mail if this is after hours You may be rapidly reaching the conclusion that everyone has too many devices too many numbers and too little time Sometimes modern com munications technology seems to have forgotten the main reason for using it to communicate with another person more conveniently People have more options available to them today for com municating with each other than ever yet they often have a harder time getting through The selection of choices spans a dizzying array of technologies and devices that can deliver voice e mail instant messages and even video Simply picking up the phone still works but now users have more choices for deciding how to reach somebody and ironically that is the problem SIP guide 6 SIP Communications For Dummies Avaya Custom Edition With people more widely available and more connected than ever before an unintended and unexpected communications paradox has emerged Users need to manage multiple identi ties for each of the devices and networks that they want to use Determining the best way to reach a person and managing a contact list for these multiple identities can be staggering Simply put communications today has become device cen tric not us
48. guide 3 4 SIP Communications For Dummies Avaya Custom Edition Icons Used in This Book MBER N g SAL STU p S A SNA AT ar Throughout this book I occasionally use icons to call atten tion to material worth noting in a special way Here is a list of the icons along with a description of each Some points bear repeating and others bear remembering When you see this icon take special note of what you re about to read This icon indicates technical information that is probably most interesting to IT professionals If you see a tip icon perk up you re about to find out how to save some aggravation Where to Go from Here No matter where you are in your SIP project always keep your eye on the big picture Avaya has keen vision and lead ership in the communications industry You can learn a lot from this book but a lot more from Avaya professionals Turn the page and discover for yourself why Avaya is one of the leaders in converged voice and data environments powered by SIP SIP guide Part 1 The Case for SIP In This Part Defining SIP Connecting people anywhere anytime on any device Facilitating interoperability Streamlining communications with or without servers Preparing for the future of SIP D you increasingly feel like your communication devices are holding you hostage Just as you finish checking your multiple voice mailboxes you get an instant message from someone that you just le
49. h protocol is the Session Description Protocol SDP which carries within it informa tion about the session that you re setting up namely the type of media the codec to use and the protocol for actually transporting the media SIP guide Part 2 SIP at a Glance 1 7 A SIMPLE Presence Solution One of the key SIP extensions defined by the IETF is SIP for Instant Messaging and Presence Leveraging Extensions or even more simply SIMPLE SIMPLE defines functions for presence and instant messaging In an advanced communications network users can specify their communications preferences and availability This feature is known as presence an intelligent network overlay that makes it easy for a calling party to reach an available and willing to be called party Presence streamlines the communica tion process by enabling users to inform others of their status their availability and how they can be contacted before a com munication session even begins Many devices can provide presence information and it becomes extremely powerful when integrated across all of the user s communication devices such as IP phones cell phones softphones PDAs and wireless Bluetooth appliances As Part 5 explains realiza tion of such a vision requires not only open interoperability but also well built ecosystems that promote cooperation between many industry players standards and protocols Presence is not limited to a single user it
50. hat the called party has been alerted A speech to text tool can convert the voice mail message to a text based IM or e mail message again depending upon the presence of the recipient Coupling presence servers with application servers will add much more decision making intelligence about where the message should be delivered improving the speed at which users respond and communicate Communication Systems That Learn MBER N g As users acquire more SIP enabled means of communication and as applications become SIP and presence aware users could be crushed under an avalanche of messages some of which are vital and others of which are not So SIP will help devices and applications become smarter about prioritizing With more devices and applications using SIP the rules for presence will become increasingly complex Software applica tions for managing presence and what to do when users or applications want to c8Aguinticate at all times of the day and Part 7 SIP and the Future of Intelligent Communications 59 night will improve accordingly It is likely that tools that manage and aggregate presence will emerge in the coming years to manage and aggregate presence from multiple sources As presence management tools evolve they may take on learning characteristics that is catching on to user habits from heuristics or patterns of usage Instead of relying upon a static set of business rules they will adapt to changi
51. hone Status Off Hook or the status of a user User Status Online Presence for composite entities like contact center groups or shared docu ments can be similarly represented SIP guide Part 3 How SIP Transforms User Communications 25 Presence means being there for your customers Every company wants to retain cus tomer loyalty through superior cus tomer service but how can your agents keep all of the info they need for accurate responses A credit card company is especially under pressure to perform 24 7 for helping customers keep accurate tabs on transactions Imagine how SIP presence can help in this scenario A customer planning a trip overseas calls his credit card company with a complex question on monetary conversion rate policies The call center agent checks her finance expert presence tab and sees that internal resident experts are off the phone and available for con sultation The agent clicks the IM tab and is automatically routed to one of the available experts for an instant messaging session The agent then gets and quickly relays the expert s answer to the customer s question Surprised at the quick response the customer then asks a question regard ing a disputed transaction with a merchant The call center agent brings up the merchant information which displays the presence and availability of the merchant s call center agents for phone calls or IM and quickly identi fies an a
52. hough SIP may end up being invisible to end users SIP is the glue that will help peer to peer communications work better than most people can imagine today We believe that most organizations will be using SIP within the next few years If you re considering using SIP in the near or distant future this part helps you understand the most important benefits of using SIP and will help you explain those benefits to other decision makers in your organization Presence Gased Communications SIP adds intelligence to communications by enabling users as well as applications to intelligently connect parties based on their presence availability We explain how presence works in Part 3 SIP also has the abilit Rq sidpport intelligent forking that is the ability to route communications to the right person using 62 SIP Communications For Dummies Avaya Custom Edition the right medium voice video IM on the right device and at the right time Turn to Part 3 for more information on SIP forking Preference Based Communications Like SIP presence SIP adds intelligence to communications through giving users control over the parameters of their com munications such as time of day preferred medium preferred callers and so on This concept is best exemplified through SIP s ability to enable you to control who contacts you on what devices If your users want more control over their com munications environment instead of
53. icates all the users and sets policies for reasonable use A SIP equivalent of caller ID is possible in this model enabling users to trust calling party indications This practice avoids the anarchy of e mail in which anyone can claim to be anyone else and the resulting avalanche of spam With policies in place an enterprise can control how much of its communica tion is routed over SIP and to whom An alternative to federation is direct peering In this mode two enterprises get together exchange directory and routing information between them and set up policies and proce dures for communication Although this system may work among a handful of large enterprises this bilateral arrange ment does not work fp huasireds and thousands of enter prises It obviously does not scale like a federation does 40 SIP Communications For Dummies Avaya Custom Edition TEC Aea Federation allows these islands of SIP communications to grow and expand and interconnect Businesses can maximize the services and features from their SIP products and sys tems and participate in the growing SIP communication ecosystem Mapping Phone Numbers to URIs sol S TUp When interconnecting islands of SIP your network needs a method of discovering a SIP URI from a telephone number The ENUM protocol has been developed to fulfill this purpose The ENUM protocol is the result of work of the Internet Engineering Task Force ETF Telephone Number Mappi
54. is considered a mature protocol it isn t 100 percent complete as a standard Standards are still i 7 being developed especially in the privacy and security areas and enhancements to the feature set will continue for the foreseeable future For example the IETF is still finalizing some fundamental architecture decisions regarding SIMPLE see Part 3 for more Shot this instant messaging protocol hh SIP Communications For Dummies Avaya Custom Edition Generally SIP adopting companies can expect a greater likeli hood of interoperability among proxies phones and gateways This integration is quicker and easier because these devices are modeled after traditional telephony devices with more predictable features and logic Interoperability for other services such as firewalls Interactive Voice Response systems IVRs and conferencing servers is less proven because these applications aren t as rigorously tested at interoperability events Because these types of products tend to have more advanced and proprietary fea tures than familiar voice centric products interoperability with these types of applications will be more complicated In such cases the application level logic built into these sys tems is much more complex than simply setting up a session Important supporting protocols such as those being devel oped within the XCON working group for centralized confer encing are being developed in the IETF External from the E
55. ital 3 starting an Photogr aphy eBay Business DUMMIES pues 0 7645 1664 7 0 7645 6924 4 Also available Bass Guitar For Dummies 0 7645 2487 9 Diabetes Cookbook For Dummies 0 7645 5230 9 Gardening For Dummies 0 7645 5130 2 Guitar For Dummies 0 7645 5106 X Holiday Decorating For Dummies 0 7645 2570 0 Home Improvement All in One For Dummies 0 7645 5680 0 Also available 2005 Online Shopping Directory For Dummies 0 7645 7495 7 CD amp DVD Recording For Dummies 0 7645 5956 7 eBay For Dummies 0 7645 5654 1 Fighting Spam For Dummies 0 7645 5965 6 Genealogy Online For Dummies 0 7645 5964 8 Google For Dummies 0 7645 4420 9 Separate Canadian edition also available t Separate U K edition also available SIP Marketing For Dummies 0 7645 5600 2 1 Personal Finance For Dummies 0 7645 2590 5 Project Management For Dummies 0 7645 5283 X 1 Resumes For Dummies t 0 7645 5471 9 Selling For Dummies 0 7645 5363 1 1 Small Business Kit For Dummies t 0 7645 5093 4 Office 2003 All in One Desk Reference For Dummies 0 7645 3883 7 1 Outlook 2003 For Dummies 0 7645 3759 8 1 PCs For Dummies 0 7645 4074 2 TiVo For Dummies 0 7645 6923 6 Upgrading and Fixing PCs For Dummies 0 7645 1665 5 Windows XP Timesaving Techniques For Dummies 0 7645 3748 2 Knitting For Dummies 0 7645 5395 X Piano For Dummies 0 7645 5105 1 Puppies For Dummies 0 7645
56. ition is best suited for small offices who desire select com munications features The solution complements Avaya s existing SIP product portfolio fits into the vision of providing customers one common user experience across devices and appli cations one X and is another step in Avaya s plan to make intelligent com munications applications available to all customers regardless of size Peer to peer technology is an important communications style and this new solution clearly illustrates Avaya s determination to maintain leadership in IP telephony innovation For example with Quick Edition set ting up a phone system has never been easier All you need to do is plug your Quick Edition phones into the network Within minutes the phones themselves Discover each other Assign extensions and populate a company directory Set up voice mail automatically You re done You can pick up the phone and use it SIP guide Part 6 SIP and Server Free Communications 53 Peer to peer technology also enables sophisticated backup of phones and voice mail Remarkably you can achieve all this with no significant additional performance burden on the net work The peer to peer solution can easily grows with the needs of your business As you add employees simply add additional telephones it s that simple Although peer to peer SIP does not require a server it can work with SIP proxy servers such as Avaya SIP Ena
57. ittle protocol developed in academia back in the mid 1990s by such thinkers as Henning Schulzrinne and Jonathan Rosenberg The authors have done an excellent job of explaining the what why and how of SIP in an understandable way Enjoy your read of SIP Communications For Dummies Avaya Custom Edition Alan B Johnston February 2006 SIP guide Introduction magine a communications environment where a central directory server not only knows how to reach an individ ual s work phone cell phone and pager but also her instant messaging IM program e mail and PDA Not only that but also imagine that the central directory server also knows a party s communication preferences and capabilities and can intelligently alert a called party when someone is trying to reach her Finally imagine that phone calls to an unavailable person can be intelligently rerouted to another person or group depending upon a number of interrelated factors such as time of day whether the called person is scheduled to be in a meeting or whether one or more of her modes of com munication is unreachable These capabilities aren t some dream of a far off utopian future but are available today thanks to a remarkable advance in communications Session Initiation Protocol SIP SIP is the glue and the intelligence that makes these advanced communications capabilities possible Vendors are rushing to incorporate SIP into their products including
58. net Engineering Task Force IETF has a work group that is working to standardize the SIMPLE protocol SIMPLE is based on RFC 3428 3265 and 3856 but is being enhanced SIMPLE is increasingly used to interconnect with previously closed public IM networks Another protocol called XMPP or Extensible Messaging and Presence Protocol was designed and is currently maintained by the Jabber Software Foundation In 2004 the XMPP work ing group at IETF published the RFC documents 3920 3921 3922 and 3923 to standardize the core XMPP protocol Gateways can be used to interconnect XMPP and SIMPLE IM networks As SIMPLE progresses and as companies like Avaya continue to add versatility features to communications products presence will likely give way to rich presence where commu nications are available anytime anywhere and through any application For example a company s materials handling appli cation can automatically notify a manager when a particular shipment has been received the application can use SIP pres ence to make a decision on how to construct and deliver the notification depending upon the mode of communication that is available at the time One Protocol Many Modes of Communication Instant Messaging IM is one of the most popular modes of real time communication Consumer IM solutions using pro prietary protocols have been available for some time but such systems suffer from security privacy reliability and fun
59. nferencing Here we explain the con cept of trunking that is connecting enterprises IP based communications systems together over long distances We also discuss ENUM the protocol that bridges the new SIP based URI system with the old TDM phone number system Part V SIP Interoperability discusses the principles needed to support an enterprise migration to SIP No two enterprises are alike so it would be difficult to come up with a single works for all recipe for migrating to SIP Instead this part explains what vendors are doing to make multi vendor inte gration with SIP as straightforward as possible Part VI SIP and Server Free Communications discusses how small businesses and distributed offices can take advan tage of SIP features even without dedicated servers Part VII SIP and the Future of Intelligent Communications looks into the future of SIP and how it will continue to evolve and improve embracing more communication technologies and supporting more enhanced communications capabilities Part VIII Top Ten Reasons for SIP Enhanced Communications offers a condensed list of the most impor tant reasons to put your communications on steroids SIP will make your communications more intelligent than anything else available today This intelligence pays off in more effec tive communications that result in happier customers and more productive employees If you re still sitting on the fence about SIP start here SIP
60. ng working group The charter of this working group was to define a Domain Name System DNS based architecture and protocols for mapping a telephone number to a Uniform Resource Identifier URD which can be used to contact a resource associated with that number ENUM has a DNS based architecture and protocol by which standard telephone numbers can be expressed as a Fully Qualified Domain Name FQDN in a specific Internet domain defined for this purpose e164 arpa The result of the ENUM query is a series of records defined in RFC 3402 that gateways proxy servers and even SIP endpoints can use to contact one or more resources for example URIs associ ated with that number ENUM and service providers As SIP becomes increasingly popular with service providers ENUM will likely become part of the suite of services that a service provider connecting to a SIP Enterprise Network can deliver through the PSTN On your SIP phone you ll be able to punch in a URI for your friend s TDM landline or cellular phone and the carrier s ENUM server will magically connect you SIP guide Part 4 How SIP Transforms Enterprise Communications 4 ENUM alternatives Until ENUM or a similar standard is widely adopted by serv ice providers enterprises using SIP can leverage existing solu tions such as LDAP Lightweight Directory Access Protocol to store both a user s URI and all associated phone numbers E 164 addresses SIP applic
61. ng con ditions such as volume and source of messages and make changes to user preferences automatically Location Based Services Presence will enable new location aware services for con sumers and enterprises Devices and SIP presence servers can interface with cellular carriers location based services which are used for E911 among other things to obtain and act on a user s approximate geographic location Also presence enabled wireless access points and micro cellsites can sense that a user is roaming within his service area and inform SIP presence servers of a user s approximate location For example when a mobile user enters a conference room with a presence enabled Wireless Access Point or micro cellsite his presence can be sent to a SIP enabled room scheduling system The system can check to see whether the meeting room is reserved if it s not the system can IM the user asking how long he would like to reserve it If the room was already booked an IM can be sent to the user s PDA informing him that the room is booked and by whom and offering alternate locations that are close by Ensuring Privacy Privacy becomes a major concern as presence is enabled on multiple user devices Users need ways to control their environments so as not to be buried by spam spyware or interruptions With a personal profile manager users will be able to control presence settings for all their devices from a secured pers
62. nies integrate voice and data over IP and link their sites using IP WANs to reduce costs for communica tions within the enterprise However traditional PSTN circuits are still used to communicate with their customers and sup pliers partners and the outside world Transforming trunking with SIP SIP trunks enable enterprises to carry their voice data over a pure IP connection to carrier clouds rather than through separate circuits as has been the practice for decades An Enterprise SIP proxy peers with a Carrier SIP proxy with the SIP guide 36 SIP Communications For Dummies Avaya Custom Edition appropriate federations and security protections established between them The IP circuit continues to carry e mail Internet and other corporate traffic as it does today and voice is simply layered on top of the circuit as another IP application SIP sets up and tears down voice calls to and from the enterprise over this IP circuit On net calls traverse the carrier s VoIP backbone which is typically dedicated to voice so that voice quality can be guar anteed Off net calls ride the carrier IP network until the last mile where a gateway converts VoIP to TDM for calls to PSTN parties see Figure 4 1 PSTN Long Distance SIP Proxy IP Data Telephony All Communications Router 4 Service Provider SIP Network PSTN Local Access Figure 4 1 SIP trunks
63. ntactis online and available for a phone call and she initiates a connection Her contactis out in the operations center so the net work intelligently forks the connection over to his PDA which contains a SIP telephony client and the call begins SIP guide Part 4 How SIP Transforms Enterprise Communications In This Part Understanding how SIP and the PSTN work together Getting familiar with SIP trunks Federating SIP islands Matching up phone numbers to URIs Ss will fundamentally improve the efficiency of communi cations between enterprises and their partners suppli ers and customers The initial wave of VoIP benefits has been primarily limited to intra enterprise communications Communications between enterprises even those that are VolP enabled still require a circuit switched handoff that impacts voice quality adds complexity and introduces unnecessary expense through intermediate carriers But SIP promises to change all of that This chapter discusses how the worlds of SIP and the PSTN public switched telephone network will be intercon nected and how enterprise communications will change through the introduction of SIP trunk services and federation services SIP guide 34 SIP Communications For Dummies Avaya Custom Edition Working Together SIP and the PSTN Clearly the telco world with its country codes area codes city codes and telephone numbers will continue to serve many people f
64. nterprise Interoperability with the PSTN is achieved through gateways and through SIP T a protocol used to carry ISDN signaling within SIP messages Connecting carrier SIP networks to enterprises is possible today as described in Part 4 However because so many implementation options in carrier and enterprise devices exist several interoperability hurdles remain Some enterprise communications vendors including Avaya are actively promoting programs that encourage interoper ability with carrier networks Avaya cofounded SIP Connect now part of SIP Forum to define rigorous standards for the carrier to enterprise interface Through its SIP certification program for service providers Avaya has tested and certified interoperability with a number of service providers SIP Interoperability Efforts SIP is an open standard and the up and coming stan dard for VoIP and oth ifage of peer to peer and group Part 5 SIP Interoperability 45 communications Like TCP IP in the 1980s and the World Wide Web in the 1990s communications hardware and software product vendors are adding SIP capability to their products Issues being worked out today include Development of a reference architecture of common network elements Specification of the basic protocols and protocol extensions that must be supported by each element of the reference architecture Specification of the exact standards associated with these protocols 1 Speci
65. officephone big company com The UAS at host officephone bigcompany com asks John whether he wants to accept the call John may hear a ring see a text message or see a blinking LED John s acceptance is sent to the proxy server The proxy server sends the acceptance to Michael Michael s UA responds to the acceptance with an ACK acknowledgement which tells the proxy server and John s UA that Michael is ready to start the call At the end of the conversation John hangs up his phone His UAC sends a BYE message to Michael Michael s UAC responds with a BYE message which ends the session Though this call flow describes the initiation of a phone call the beauty of SIP is that the same basic call flow would also apply for establishing video conferencing or other media sessions SIP guide Part 3 How SIP Transforms User Communications In This Part Getting familiar with presence enabled communications Routing communications with presence Choosing your modes of communication freely Recognizing benefits for the mobile user Ps part describes in detail how SIP presence and user preference can enhance the productivity and quality of communications and explains the concept of user centric communications To Be Available or Not to Ge Available Presence Enabled Communications When a user activates his or her communications device user agent or UA it registers its presence on the network
66. on information Checking a user s calendar to see whether he is in a meeting or on vacation Checking a user s e mail to see whether he is reading or sending e mail or whether he has an Out of Office setting SIP uses presence to make routing decisions for a variety of incoming communications including Routing incoming calls from a desk phone to a cell phone if the user has indicated that he is roaming and prefers calls routed as such Classifying nonurgent incoming communications as polite calls that the user can choose to answer defer or ignore Routing urgent incoming calls and e mail to backup support if the user is on vacation or in an extended meeting When a SIP proxy a server that processes and forwards SIP requests between calling and called parties receives an INVITE request to communicate it uses the called party s presence to make a routing decision sometimes called forking The forking decision may be to a specific party an intelligent fork or it may send several INVITEs to different addresses parallel forking gonBen Forking is an old UNIX term where a process clones itself into two or more new processes In the SIP context forking refers to SIP s use of sending multiple simultaneous INVITEs to other parties in an attempt to initiate a communication session SIP guide x s Tlga TECH x s Tg TECy A Ol Part 3 How SIP Transforms User Communications 2 7 The Inter
67. onal portal They can set preferences to allow or deny others to seethgixgaresence based on time of day 60 SIP Communications For Dummies Avaya Custom Edition ar location the device they re currently using and other factors Such control will help to address big brother type privacy concerns Personal profile managers will need to be aware of privacy requirements in various parts of the world and alter their behavior accordingly The Internet Multimedia Subsystem The Internet Multimedia Subsystem IMS the Third Generation Partnership Project s 3GPP next generation wireless wireline communication services reference architecture is a highly visible example of how SIP is enabling new services IMS is a standard architecture for telecom operators to provide next generation mobile and fixed multimedia services It uses a VoIP implementation based on a 3GPP standardized imple mentation of SIP all running over IP IMS will not only provide new services but all the services that the Internet provides Users will be able to access their services when roaming as well as from their home networks SIP guide Part 8 Top Ten Reasons for SIP Enhanced Communications In This Part Simplifying communications Gaining more control Working with divergent systems Making mobility easier Saving money Ss is a key enabling technology that can advance communi cations to an unrealized level of flexibility and usefulness Even t
68. ons today are device centric Every device has its own phone number address or alias The more devices you use the more addresses others need to remember in order to reach you And without presence as described in the previous section communication becomes a guessing game when trying to connect with people wherever they may be and whatever they re doing SIP guide 8 SIP Communications For Dummies Avaya Custom Edition Do we need fold out business cards You probably don t consider yourself a communications geek but like most modern business people you proba bly have many ways to communicate with others For example a typical salesperson may have Three phone numbers home work cell 1 Text messaging and e mail on a PDA 1 M identities on Yahoo Google MSN and AOL 1 M capabilities on a laptop and on a cell phone Four e mail addresses All of these identities operate in silos none is aware of any other The salesperson s communications capabilities have not become easier but more difficult because of the lack of integration between all of these media types SIP promises to bring all of these capabilities and more back together With SIP communications become user centric once again A SIP address of record AOR provides one unifying identifier that can be mapped across multiple devices and media types You can think of an AOR as the user s public address Part
69. or some time to come So how do you call SIP users with URIs from old push button phones and how do you call landline users from SIP enabled devices Fortunately the mapping between SIP and telephony proto cols has been defined Gateways that link the Internet with the PSTN are widely deployed and used by VoIP users every day SIP URIs can also be used to carry telephone numbers For example sip 12025551212 example com user phone contains the phone number for directory assistance in Washington D C By porting a PSTN telephone number to a SIP PSTN gateway incoming telephone calls can be routed to SIP phones call managers and PBXs Service providers have already adopted SIP for their internal PSTN telephone call routing With S P to PSTN interworking providing connectivity between these two systems through a defined interface standard now in place carriers such as Global Crossing AGN Networks and others are working with equipment vendors like Avaya to offer exciting new SIP trunk services to the enterprise market Trunking with SIP Trunking refers to the means used to transport inbound and outbound calls between the enterprise and external entities including branch offices and other remotely located parties such as business partners customers and suppliers In this section we describe the differences between traditional and SIP trunks as well as some of the characteristics of SIP trunks that are attractive to businesses
70. participants to submit queries or make changes in the appli cation Cool huh When coupled with unified communications across multiple access devices presence will fundamentally change the way people communicate SIP guide Part 7 SIP and the Future of Intelligent Communications 57 Seamless Use of Multiple Devices MBER SIP presence will improve the productivity of businesspeople by enabling them to seamlessly use multiple communication devices Today most users view the presence status of a buddy only as it pertains to their IM desktop status resulting in inefficiencies in the way they communicate For example they waste time playing voice e mail tag and by instant mes saging someone simply to ask can u talk SIP provides options to collect and advertise presence and preferences in a buddy list but the presentity can now be a desktop a mobile phone or another PC application With a unified approach SIP will show the presence on whatever device the user happens to be using instead of simply being idle or out to lunch based only on the desktop status Also devices will be smarter and aware of their owners preferences including which modes to communicate in depending upon a variety of conditions For example if you were present on your cell phone but not your desk phone your buddy would know to click to call you instead of instant messaging you while you re moving 60 miles per hour down the f
71. phical User Interface in a screen phone as opposed to using the tele phone keypad to control the presentation of the voice messages 1 Speech to text translation In situations where the caller has only a phone and the called party has only a text ter minal a SJP enabled translation service could provide text to speech and speech to text translation 1 Web based Interactive Voice Response IVR Users may surf the Web as opposed to working their way through IVRs Such systems could be used from a hotel room to order services for instance Making the Most of User Preference Another differentiating aspect of SIP is user preference In the SIP world you can specify all options for communication and those options function as a single tool In other words the user controls how calls are handled where they are routed and the type of communication used Some of the ways you can specify preferences include Y Buddy lists People on your communications buddy list can be given preference priority or additional choices for communication mode Time of day You can specify modes of communication based upon the time of day of communications For example you might accept a nonurgent call on a cell phone during the day but after hours direct it toa voice mail or IVR system 1 Preference influenced multimodal communications You can choose which medium of communication you want to use or respond with based upon a wide number
72. r either a text or a voice message New SIP enabled converged communications solutions will enable users to interact with each other or with an appli cation in a variety of ways input with speech keyboard telephone keypad mouse and or stylus and output such as synthesized speech audio plain text motion video and or graphics Here are some examples that SIP enabled solutions can facilitate 1 Voice IM video A common interface provides access to instant messaging voice and video services tied together with presence Initiating communications is the same for all modalities and users can switch from one communication method to another on the fly to best meet their needs perhaps within the context of a single communication session 1 Inline translation services A SIP request originating with an English speaking user might contain a Web Services request to translate a message into another language for a non English speaking recipient Multimodal messaging A SIP enabled voice messaging system could provide additional features such as e Voice mail headers to the end user via text e Display enhanced voice mail by delivering text or graphics mensgipetead of voice based menus Part 3 How SIP Transforms User Communications 29 e Virtual Business Card with every voice call so that the user can have the caller s contact information available e Playback skip rewind pause slowdown and speedup buttons using a Gra
73. r networks by using a user s known physical location to make even better decisions about the initiation of communication sessions We don t want to give away all of our predictions here Turn to Part 7 for more prognostications about SIP SIP guide Part 2 SIP at a Glance In This Part Working with existing protocols Extending SIP to multimedia sessions Getting to know SIP presence Examining SIP components Following an example of basic operations RY EY Ss is an application layer Internet protocol for establishing manipulating and tearing down communication ses sions You can do a lot more with SIP than set up telephone calls The protocol is designed to be extensible meaning SIP can be easily extended to accommodate video instant messaging IM and yet to be invented communications media and features XML is an example of another extensible language Aside from supporting communication call setup and tear down SIP also currently supports extensions for instant messaging as well as advertising and tracking user availability both familiar today in Yahoo and AOL Instant Messenger SIP is used to identify locate and enjoin parties who wish to communicate using any peer to peer media type However SIP does not transport the media itself that is handled by codecs within the communications programs or devices SIP guide 14 SIP Communications For Dummies Avaya Custom Edition gt ann w F
74. reeway Presence refers to the ability for SIP based communications to become smarter by facilitating communications based upon a user s preferences and ability to communicate Presence PBX Integration When SIP SIMPLE IM is integrated with an IP PBX desktop presence will include the on off hook status of the buddy s phone all in the same buddy list This use of presence means that a caller can see whether his buddy is on the phone or not eliminating blind phone calls or e mails SIP guide 58 SIP Communications For Dummies Avaya Custom Edition Combining presence from multiple SIP devices will inform the caller that the user is present or not but the caller will not need to know on which number to call his buddy He simply launches a message to sip buddy company com and the SIP server will start the session with the correct device cell phone desk phone IM at the correct time using the correct mode of communication voice text video and so on Further Optimization As more applications devices and networks become SIP aware communications will be further optimized For instance presence aware messaging servers could sense that the called party is available on his IM client but not on the desktop phone that was being called As a caller leaves a voice mail message instead of simply dropping the message in an inbox an IM may be sent telling the called party that a message has arrived and to the calling party t
75. the peer to peer overlay network when a call to the phone or user is made Y Dynamically sharing information when peers join and leave so that the load is balanced across peers and so that the sudden loss of one or more peers doesn t cause the peer to peer network to lose track of its cur rent registrants Figure 6 1 shows how this process works Teleworker VoIP Carrier PSTN Gateway ex 6 1 The peer to peer SIP discovery process SIP guide 52 SIP Communications For Dummies Avaya Custom Edition Reaping the Benefits of Peer to Peer SIP Communications With peer to peer SIP technology you can dramatically simplify telephone system setup and installation Plug the IP telephones into the local area network and the system configures itself In minutes all users have access to the most commonly used set of features including voice mail confer encing auto attendant and call management A simple PSTN gateway also acts as a peer to the phones and can provide access to the PSTN By distributing the workload out to the telephone system peer to peer SIP increases reliability by eliminating the problem of a single point of failure wreaking havoc on the entire system Avaya one X Quick Edition Avaya recently announced a new solu tion Avaya one X Quick Edition that is based on peer to peer technology and can serve both very small businesses and small branches of larger enter prises Quick Ed
76. these challenges and the ways in which SIP based solutions can be effective in small and distributed business environments Meeting Challenges for Small Offices Small offices including very small businesses and small branches of enterprises are becoming more dynamic in form and function and are becoming increasingly distributed These new work environments introduce challenges including YY Capital Costs As small offices seek to maintain a more dynamic form that focuses on the localized needs of their markets they often find themselves balancing the need for adaptability with the upfront capital costs of communications solutions 50 SIP Communications For Dummies Avaya Custom Edition Deployment and Administrative Costs Communications solutions often require on site technical installation serv ices Additional costs are incurred when local support is required to fix problems add capacity or perform basic administrative tasks Speed For many small offices competitive advantage is all about speed time to deployment drives time to market In contrast communications solutions deploy ment is a relatively time consuming event often requiring detailed planning staging and manual administration Business Continuity Business relies on resilient com munications that work Though available business continuity often requires additional upfront capital costs Risk Aversion Small businesses are more sensitive to
77. ts test events at locations around the world More information is available at http www sipit net 1 SPEERMINT is a new Operations Area working group in the IETF that is working on peering and operational issues of SIP Find out more at http www ietf org html charters speermint charter html These are just a few of the efforts that are helping to acceler ate the already rapidly growing adoption and reliability of multi vendor SIP environments Multi Vendor Integration One of the challenges many enterprises deal with today is the issue of multi vendor PBX networking Traditionally intercon nection has required the use of Q interface Signaling protocol QSIG to enable support of supplementary services between systems This approach provides limited features between systems but it doesn t address the management complexity caused by the duplication of features and systems or the user training complexity due to different user experiences with each system SIP promises to make all of this much easier with some caveats of course Because it is so open SIP provides enter prises with more choices for user devices and connecting applications But although SIP enables basic functionality between some vendors proxies and other vendors phones for example it isn t yet the silver bullet for all interoperability challenges Some applications are just too complicated for SIP gout Remember SIP is designed to simply set up
78. vailable agent who can look up details of the transaction and send it back via a Web page push The cus tomer provided with this information now remembers not only the transac tion but also leaves with a lasting impression of the responsiveness and expertise of the credit card company Using Presence to Route Communications SIP is unique in its ability to make call routing decisions based upon presence As Part 2 explains in detail presence enables users to inform others of their status availability and how they can be contacted before a communication session even begins When integrated with telephony a user can com municate status and availability to others through multiple devices such as IP phones cell phones softphones pagers video conferencing e mail wireless devices and even TDM phones when tied into an intelligent IP PBX SIP guide 26 SIP Communications For Dummies Avaya Custom Edition Presence can span a number of different communication channels The aggregated view of a user s presence that is the availability across all of an individual s SIP enabled devices is called Multiple Points of Presence or MPOP MPOP becomes powerful when presence is inferred from observation of a user s actions Possibilities include Setting the user s status to Away when his phone and keyboard are inactive for some time YY Making inferences about a user s presence through mobile device locati
79. xternal connectivity will lead to a SIP guide 9 0 SIP Communications For Dummies Avaya Custom Edition transformation in communications between an enterprise and its ecosystem of partners suppliers and customers SIP may eventually become the unifying protocol for all com munications You can find more information about SIP trunks connectivity to PSTN networks and connecting enterprise islands in Part 4 Simplifying Communications Architecture MBER KO amp Communications networks today are complex and costly to operate When you begin investigating ways to transition to SIP telephony you may feel rather bewildered by the array of protocols gateways security constraints and quality of service issues A considerable effort is required to plan build and operate these multiple media streams that often coexist on shared physical networks Rush hour traffic grid lock by comparison is an easy problem to solve SIP offers the promise of a single unifying protocol for all communications With SIP being widely deployed in both service provider and enterprise networks the need for gate ways that translate one protocol to another for example IP to Time Division Multiplexing or TDM is eliminated Proprietary signaling protocols give way to a single standard interface for all connectivity whether for adding endpoints deploying contact center adjunct services or even connect ing to trunk services for extern

Avia Tablet Accessory Avaya Custom Edition User's Manual

Contents

Download Pdf Manuals

Related Search

Related Contents