Getting Started - Community RTI Connext Users
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1. so it s important to check the writerEntityld of the DATA packet to confirm that the partic ipants in question have discovered the reader writer correctly Lastly it s important to check whether the topic and type declared in the meta data of the reader matches that in the meta data of the writer Assuming that neither party is deliber ately ignoring certain Entities e g Participant Topic DataReader DataWriter if all these were acknowledged with ACKNACK packets the reader participant should at this point be ready to accept user data from the writer and the writer will send the data to the reader Exactly when the data will appear on the wire will depend on when the writer writes the next sample as well as the QoS of both the reader and writer L The writer is writing your data but the reader is not able to access that data when it calls read or take In this case you should check your QoS settings Compare the writer s QoS against the reader s Perhaps the minimum separation in the TimeBasedFilter QosPol icy of the reader is inadvertently filtering out received issues LJ Once a writer is writing user data to a data reader the initial discovery phase is over But there can be an anti discovery problem depending on the Liveliness QoS Connext may purge a remote entity that it considers to be stale Regardless of what kind of liveliness setting you use the main idea is to ensure that your participant and its entities renew2. Contains information regarding the values of a batch of application data objects DATA FRAG DATA SESSION Contains a fragment of information regarding the value of an application Data object In RTI Data Distribution Service 4 2e and higher and in Connext 4 5f and higher a new for mat is used captured submessages of the earlier format are displayed as DATA FRAG deprecated Contains information regarding the value of an application Data object when sent by a multi channel Writer 5 2 Displaying Packets Table 5 1 RTPS 2 x Submessage Types Submessage Type Description GAP Describes the information that is no longer relevant to Readers HEARTBEAT Describes the information that is available in a Writer HEARTBEAT BATCH Describes the information that is available in a Writer for batched data HEARTBEAT SESSION Describes the information that is available in a multi channel Writer HEARTBEAT VIRTUAL Describes the information that is available from virtual Writers Provides information about the source from which subsequent Entity submessages INFO SOURCE iis originated INFO DST Provides information about the final destination of subsequent Entity submessages INFO REPLY Provides information about where to reply to the entities that appear in subsequent submessages The locator provided is limited to contain a single UDPv4 address and port Provides informatio
3. INFO TS DATA p INFO DST ACKNACK INFO DST HEARTBEAT INFO TS DATA p INFO TS DATA p INFO DST HEARTBEAT INFO DST HEARTBEAT Destination unreachable Port unreachable INFO DST ACKNACK INFO DST ACKNACK INFO DST ACKNACK INFO TS DATA p INFO TS DATA p INFO DST HEARTBEAT INFO DST HEARTBEAT INFO DST HEARTBEAT INFO DST ACKNACK INFO DST ACKNACK INFO DST ACKNACK INFO DST HEARTBEAT INFO DST HEARTBEAT INFO DST HEARTBEAT INFO DST ACKNACK INFO DST ACKNACK INFO DST HEARTBEAT INFO DST HEARTBEAT INFO TS INFO DST DATA r HEARTBEAT INFO TS INFO DST DATA W HEARTBEAT INFO DST ACKNACK INFO DST ACKNACK INFO DST ACKNACK INFO DST ACKNACK PING INFO TS DATA INFO TS DATA INFO TS DATA 5 14 Analyzing Packets from Connext Applications Table5 5 Analysis of Sample File s Packets Direction Packet Description When the writer participant learns about the new reader participant it uses HEARTBEATs and ACKNACKs from its builtin discovery endpoints to tell the 19 20 reader participant about the writer and readers it has First it tells the reader participant about its builtin participant liveliness reader packet 19 and writer packet 20 Repeat announcements about the writer participant which reduce the chance 21 22 that the newly created reader participant will drop the reply fro
4. 65 10 10 100 65 10 10 30 100 10 10 30 100 10 10 100 65 10 10 100 65 10 10 30 100 10 10 30 100 10 10 100 65 10 10 100 65 10 10 100 65 10 10 100 65 10 10 100 65 10 10 100 65 10 10 100 65 10 10 100 65 10 10 30 100 10 10 30 100 10 10 30 100 10 10 30 100 10 10 30 100 10 10 30 100 10 10 100 65 10 10 30 100 10 10 30 100 10 10 100 65 10 10 100 65 10 10 100 65 10 10 100 65 10 10 100 65 10 10 100 65 10 10 100 65 10 10 100 65 10 10 100 65 10 10 100 65 10 10 100 65 10 10 30 100 10 10 100 65 10 10 30 100 10 10 30 100 10 10 30 100 10 10 100 65 10 10 30 100 10 10 30 100 10 10 100 65 10 10 30 100 10 10 100 65 10 10 30 100 10 10 30 100 10 10 30 100 10 10 30 100 RTPS2 ICMP ICMP RTPS2 RTPS2 ICMP ICMP RTPS2 RTPS2 ICMP ICMP RTPS2 RTPS2 RTPS2 RTPS2 RTPS2 RTPS2 RTPS2 RTPS2 RTPS2 RTPS2 RTPS2 RTPS2 ICMP RTPS2 RTPS2 RTPS2 RTPS2 RTPS2 RTPS2 RTPS2 RTPS2 RTPS2 RTPS2 RTPS2 RTPS2 RTPS2 RTPS2 RTPS2 RTPS2 RTPS2 RTPS2 RTPS2 RTPS2 RTPS2 RTPS2 RTPS2 RTPS2 RTPS2 RTPS2 RTPS2 RTPS2 PING Destination unreachable Port unreachable Destination unreachable Port unreachable INFO TS DATA p INFO TS DATA p Destination unreachable Port unreachable Destination unreachable Port unreachable INFO TS DATA p INFO TS DATA p Destination unreachable Port unreachable Destination unreachable Port unreachable PING PING INFO TS DATA p INFO TS DATA p INFO TS DATA p
5. RTPS2 INFO_DST ACKNACK Frame 1 106 bytes on wire 106 bytes captured Ethernet II Src Vmware 91 8e 6e 00 0c 29 91 8e 6e Dst D Link 8e 9c 06 00 15 e9 8e 9c 06 Internet Protocol Src 10 20 1 86 10 20 1 86 Dst 10 10 30 100 10 10 30 100 User Datagram Protocol Src Port 37224 37224 Dst Port 18411 18411 Real Time Publish subscribe wire Protocol 2 x E Protocol version 2 1 major 2 minor 1 vendor Real Time Innovations Inc guidPrefix 0a140156 00000625 00000001 hostid 0a140156 appId 00000625 counter 00000001 Default port mapping UNICAST USERTRAFFIC domainid 44 participantIdx 0 Submessage INFO TS Submessage DATA submessagelId DATA 0x15 E Flags 0x05 _____D_E octetsToNextHeader 28 Extra flags 0000000000000000 Octets to inline Qos 16 readerEntityId ENTITYID UNKNOWN 0x00000000 writerEntityId 0x80000003 Application defined writer no key 0x800000 wr iterSeqnumber D E E E EH DH E E E E serializedData encapsulation kind GOR LE encapsulation options 0000 serializedData 01000004 Expand the submessage details to see the sequence number and other details 5 12 Analyzing Packets from Connext Applications 5 3 2 Analyzing the Discovery Data Sample Trace Use the File Open command to open the file discoveryTrace pkt see Section 5 3 for its loca tion The sample file contains a sequence of RTPS packets that illustrate the protocol when two appli cation
6. display the decoded contents of individual packets Wireshark decodes each RTPS packet and shows you the value for each field in the packet s structure While the low level details of a packet s contents are beyond the scope of this manual this information is available in the Real Time Publish Subscribe Wire Protocol Specification see Available Documentation Section 1 1 This chapter includes the following sections I RTPS Submessage Types Section 5 1 1 Displaying Packets Section 5 2 LJ Analyzing Packets from Connext Applications Section 5 3 5 1 RTPS Submessage Types Each RTPS packet message consists of a header and one or more submessages When you dis play captured packets the Info column seen in Figure 5 1 lists the types of submessages in each packet Table 5 1 lists the submessages you may see in the Info Column The details of each type of submessage are described in the Real Time Publish Subscribe Wire Protocol Specification 5 1 RTPS Submessage Types Figure 5 1 Analyzing Packets dO J C cn E UJ hJ HA Ln E UJ NJ NJ OOO OO NNNNAN Table 5 1 RTPS 2 x Submessage Types 020581 020856 021401 021616 022254 140703 711920 992846 022182 022386 022576 10 10 The Info column shows you what submessages are in eac OxOa0a640 0x0a0a64 0e Ox0a0a640e Ox0a0a640e Ox0a0a640e Oxda0a640e Ox0a0a640e OxOa0a640e OxOada640e OxQa0a640e Ox0aQa640e Ox0ada640e R
7. initially calculated as for each peer in initial peer list peer participant i where i lt maximum participant index Since the participant s maximum participant index is 1 and the initial peer list contains only 10 10 30 100 the potential participant list is 10 10 30 100 partici pant 0 10 10 30 100 participant 1 Since each participant gets its own receive locator we send separate but identi cal packets to each potential participant listening on its own locator App1 App2 1 12 Before sending packets with participant information the participant sends to each receive locator a PING packet as packets 1 and 2 These packets serve to prime ARP tables and to see if the locators are reachable destinations Since there is no other Connext application in the system in the same domain these locators are unreachable as packets 3 and 4 Because the participant is newly created it sends its information to each locator as packets 5 and 6 These are to unreachable destinations packets 7 and 8 It then again sends its information packets 9 and 10 in accordance to its initial_participant_announcement QoS of 1 Again these are to unreachable desti nations packets 11 and 12 Similar to the writer participant when the reader participant starts Connext announces the new participant App1 lt App2 13 18 oe 9 Note the destination of the writer participant is reachable so no unreachable destination
8. only RTPS udp 8 4 0x52545053 or ip 6 2 amp Ox1FFF 0 Only UDP packets udp Only UDP multicast packets udp and ip multicast Only non UDP multicast udp and not ip multicast Only UDP from to 10 10 1 192 udp and host 10 10 1 192 Only packets from IP addresses 10 10 100 14 to src host 10 10 100 14 and dst host 10 10 100 74 10 10 100 74 For more information see Wireshark s documentation Help Wireshark Online User s Guide Note Wireshark does not validate capture filter strings as they are entered It will not alert you about an incorrect expression until after you press the Capture button It may be helpful for you to test your capture filter string with Wireshark s f argument to try a capture filter expression See Help Manual Pages wireshark For help analyzing captured RTPS packets see Chapter 5 4 2 Chapter 5 Analyzing RTPS Packets This chapter will help you interpret the submessages within captured RTPS packets There are two levels of analysis that you may be interested in J A high level understanding of what is transpiring during a sequence of captured RTPS packets This chapter will help you learn to read a sequence of packets by walking through the provided sample capture files You may also find it helpful to review the Discovery chap ter in the RTI Core Libraries and Utilities User s Manual 1 A more in depth understanding of an individual packers contents This chapter will show you how to
9. participants have discovered each other but their contained readers writers are not getting hooked up correctly In this case you may see HEARTBEAT and ACKNACK packets for the reserved meta data representing the reader and writer from one partici pant to another but the other participant is not responding back in accordance to the RTPS protocol L The objects have all discovered each other but the writer is not sending user data In this case you will see the discovery protocol complete successfully but not see DATA packets containing user data from the writer When a participant containing a writer sends meta data to other participants and those other participants respond with ACKNACK packets to acknowledge those discovery packets all you can say is that the declaration for that writer was received by all partici pants in the system But just because a participant is writing DATA packets does not nec essarily mean it is writing your application s user data Connext also uses DATA packets to propagate internal object information When in doubt check the traffic_nature field in the decoded packet to see how the packet is being used 6 1 Visualizing Your System 6 2 A subscriber reciprocally declares its reader object with another DATA packet to all con cerned participants This happens before the writer application starts publishing user data Connext uses separate built in objects to announce and discover readers vs writers
10. rtps sm wrentityId Writer entity ID as it appear in a submessage rtps sm wrentityld entityKey entityKey field of the writer entity ID rtps sm wrentitylId entityKind entityKind field of the writer entity ID rtps sm seqNumber Writer sequence number Parameters rtps param id Parameter ID rtps param length Parameter length rtps param ntpTime Any generic ntpTime used in any parameter rtps param ntpTime sec Second part of a ntpTime 5 6 Displaying Packets Table 5 2 5 2 2 Display Filter Fields for RTPS Messages Field Description rtps param ntpTime fraction Fraction part of a ntpTime rtps param topicName Topic associated with a PID TOPIC rtps param strength Value of the strength parameter in a PID STRENGTH rtps param typeName Value of PID TYPE NAME rtps param userData Raw data of PID USER DATA rtps param groupData Raw data of PID GROUP DATA rtps param topicData Raw data of PID TOPIC DATA Value of the content filter as sent in a HESPERIA PID CONTENT FILTER PROPERTY parameter Value of the related topic name as sent in a Hpspateueciere opicName PID CONTENT FILTER PROPERTY parameter Value of the filter name as sent in a R aiaa PID CONTENT FILTER PROPERTY parameter rtps issueData Value of the issue data transferred in the packets Note The domain id participant idx and traffic nature are describ
11. shows a sample Capture Options window The defaults in the Capture Option window may very well suit your needs they will capture all packets sent to the selected interface Then you can filter the displayed results with a display filter as described in Section 5 2 1 If you want to change any of the defaults for this window see the Wireshark User s Guide or online help Note The check boxes for Update list of packets in real time and Hide capture info dialog are selected by default However these features can slow down the capture pro cess and increase the chance of missing packets We recommend deselecting these two check boxes to limit the risk of missing packets 4 Click Start to start the capture session 5 To stop the capture e If Hide capture info dialog is selected click Stop on the Capture window or use the j button located on the far right of the main window s tool bar you may need to resize the main window to see it e f Hide capture info dialog is not selected click Stop in the Capture Dialog win dow With the steps above you will capture all the packets that come through your selected interface Such an indiscriminate capture session may yield hundreds or thousands of packets While modern computers are amazingly fast processing each captured packet does take a certain amount of time Filtering out uninteresting packets can help you squeeze the most out of your 4 1 Figure 4 1 Starting a Captu
12. 0 000 Data 7636 3960 Real Time Publish Subscribe Wire Protocol Routing Information Protocol 4 69 Remote Procedure Call 21 88 28 3252 0 001 0 0 0 000 Yellow Pages Service 21 88 28 3252 0 001 28 3252 0 001 Domain Name Service 6 25 8 966 0 000 8 966 0 000 V NetBIOS Datagram Service 10 16 13 3353 0 001 0 0 0 000 V SMB Server Message Block Protocol 10 16 13 3353 0 001 0 0 0 000 V SMB MailSlot Protocol 10 16 13 3353 0 001 0 0 0 000 Microsoft Windows Browser Protocol 10 16 13 3353 0 001 13 3353 0 001 NetBIOS Name Service 7 03 9 846 0 000 9 846 0 000 Hypertext Transfer Protocol 12 5096 16 5304 0 001 16 5304 0 001 Network Time Protocol 1 56 2 184 0 000 2 184 0 000 Providing Information to RTI Support 6 3 Providing Information to RTI Support If you ever need to contact RTI support for an issue related to Connext the captured packets will help RTI support diagnose the problem faster especially when accompanied by a Connext log created with a high verbosity setting See the RTI Core Libraries and Utilities User s Manual s Troubleshooting chapter for more informa tion on setting verbosity 6 4
13. BEAT RTPS OxQaQa640e 0x18880 HEARTBEAT RTPS 0xO0a0a640e Ox18880 HEARTBEAT RTPS OxOa0a640e Ox18880 HEARTBEAT RTPS OxQaQa640e Ox18880 HEARTBEAT RTPS OxOa0a640e Ox18880 HEARTBEAT RTPS O0x0a0a640e 0x18880 HEARTBEAT RTPS OxQaQa640e Ox18880 HEARTBEAT RTPS Ox0a0a640e Ox18880 HEARTBEAT nrnc duds OS C4 CS Ou 09000 Lir Anm AT Table 5 2 briefly describes the meaning of each field that can be used in a display filter for RTPS To display packets for RTPS2 change the prefix from rtps rtps2 These fields can also be used in coloring rules see Section 5 2 2 To display both RTPS and RTPS2 rules must include both versions logically OR ed together For details on the meaning of these fields see the Real Time Publish Subscribe Wire Protocol Specification see Available Documentation Section 1 1 Displaying Packets Display Filter Fields for RTPS Messages Field Description Header fields rtps version Protocol version major minor rtps version minor Protocol minor version rtps version major Protocol major version rtps domain id Domain ID of this communication see note below rtps participant idx Participant index see note below rtps traffic nature Nature of the traffic see note below rtps vendorld Vendor ID s GUID Prefix of the packet this does NOT match a GUID Prefix rtps guidPrefix from a submessage rtps hostId Host ID component of the
14. CK v 33 5 993643 10 10 100 14 y a RTPS 0xO0a0a640e Ox18880 ACKNACK p H s n amp n A E Protocol CAE major 1 RTPS minor 1 Header vendor Real Time Innovations Inc n HE guidPrefix 0a0a640e 18880001 hostId 0a0a640e appId 18880001 ManagedApplication 188800 T o Default port mapping domainId 29 participantIdx 4294967 nature 09 q E Submessage DATA 0 submessageId DATA 0x02 C B Flags M CG ADE FR OctetsTONextHeader 160 o t readerEntityId ENTITYID UNKNOWN 0x00000000 E Hj writerEntityId ENTITYID BUILTIN SUBSCRIPTIONS WRITER 0x000004c2 Oo Data t keyHashsuffix 0x00000304 Application defined reader with key 0x000003 O submessage writerseqNumber T A B serializedbata B PID TOPIC NAME Example Foo B PID TYPE NAME Foo Hj PID RELIABILITY BEST EFFORT RELIABILITY QOS E PID RECV QUEUE SIZE deprecated 0x00000400 Hj PID TIME BASED FILTER 0 sec v Hj PID LIVELINESS kind AUTOMATIC_LIVELINESS_QOS lease duration INFINITE DIIDARTI TTY VOL ATTIE NUDARTI TTY ans The Packet List pane on top lists the Seni of captured submessages The middle pane shows a decoded view of a selected packet The bottom pane shows the raw data ad any selected field in a packet You can customize these views from the View menu To change which columns are displayed select Edit Preferences User Interface Columns Available Documentation L RTI Wireshark Release Notes Please see RTI Wireshark ReleaseNo
15. P4 INFO DST INFO REPLY Range offset length Wireshark also allows you to save filter expressions for future use For more information see the Wireshark User s Guide or online help Figure 5 4 Filtering by Submessage Type 1 Use the Expression button to help you enter a filter 2 Click Apply 3 Now only packets containing a HEARTBEAT are displayed 007812 008461 008605 008741 009665 010088 010232 011622 711920 992846 713828 993371 999946 005536 609355 610037 610180 610317 614 304 B 10 10 100 14 239 192 1 2 10 10 100 14 239 102 1 2 10 10 100 14 239 192 1 2 10 10 100 14 239 192 1 2 10 10 100 14 239 192 1 2 10 10 100 14 239 192 1 2 10 10 100 14 239 192 1 2 10 10 100 14 239 192 1 2 10 10 100 14 239 192 1 2 10 10 100 14 239 192 1 2 10 10 100 14 239 192 1 2 10 10 100 14 239 192 1 2 10 10 100 14 239 192 1 2 10 10 100 14 239 192 1 2 10 10 100 14 239 192 1 2 10 10 100 14 239 192 1 2 10 10 100 14 239 192 1 2 a6 26 166 24 030 4099 3 3 Displaying RTPS and RTPS2 Messages v Expression OxOQa0a640e Ox18880 HEARTBEAT RTPS OxO0a0a640e Ox18880 HEARTBEAT RTPS O0x0a0a640e Ox18880 HEARTBEAT RTPS OxQaQa640e Ox18880 HEARTBEAT RTPS 0x0a0a640e Ox18880 HEARTBEAT RTPS 0xO0a0a640e Ox18880 HEARTBEAT RTPS 0x0a0a640e Ox18880 HEARTBEAT RTPS OxQaQa640e Ox18880 HEARTBEAT RTPS OxOa0a640e 0x18880 HEARTBEAT RTPS OxQaQa640e 0x18880 HEART
16. TPS Expand the RTPS tree click the sign to see the choices for this protocol as seen in Figure 5 3 In the Field name list select rtps sm id In the Relation list select In the Predefined values list select HEARTBEAT Click OK to close the Filter Expression window Click Apply in the main window to apply the new filter Now you will see only RTPS messages that contain a HEARTBEAT submessage as shown in Figure 5 4 5 4 Displaying Packets Figure 5 3 Creating a Display Filter Scroll down to RTPS or RTPS2 Click the sign to expand the tree Use these fields to create a display filter Field name S RTPS rtps sm flags flags bitmask representing the rtps version version RTPS protocol version n rtps version major major RTPS major protoc rtps version minor minor RTPS minor proto _ rtps domain id domain id Domain ID rtps participant idx participant idx Participa K rtps traffic nature traffic nature Nature of tF rtps vendorld vendorld Unique identifier of 1 rtps guidPrefix guidPrefix GuidPrefix of the F rtps hostld hostid Sub component hostld rtps appld appld Sub component appld of rtps appld instanceld appld instanceld insta rtps appld appKind appid appKind appKind rtps sm id submessageld defines the type of U Relation Value unsigned 1 byte is present og m Predefined values GAP INFO TS INFO SRC INFO REPLY I
17. TPS Oxda0a640e NJ SJ NJ NJ NJ UJ UJ UJ UJ UJ C O O uu NN Uy Ww ow L G MM G M M G G GB G U RM KA K KA KM KA IJ KA ISO N NN 100 14 N U uu O U J h packet contains a Reader announcement Ox18880 PEELED Ox1 8880 Ox18880 Ox18880 Ox18880 Ox18880 Ox18880 0x18880 0x18880 0x18880 0x18880 0x18880 The highlighted packet DATA P4 ACKNACK ACKNACK DATACW DATA DATA DATA HEARTBEAT HEARTBEAT NOKEY_DATA Submessage Type Description ACKNACK Provides information on the state of a Reader to a Writer ACKNACK BATCH Provides information on the state of a Reader to a Writer for batched data ACKNACK SESSION Provides information on the state of a Reader to a multi channel Writer DATA 1123 Where 1 a letter representing the entity ID P upper case DomainParticipant t Built in topic writer w built in publication writer r built in subscription writer p lower case built in participant writer m peer to peer participant message writer unknown writer Bit 1 Bit 0 Text 1 1 UD Where bit 0 Disposed flag and bit 1 Unregistered flag For example you may see DATA p 11 DATA RL D 2 3 two letters that describe the last two bits of the statusInfo inline QoS Contains information regarding the value of an application Data object The information is a fixed string with the following format DATA BATCH
18. Using Wireshark with RTI Connext DDS Getting Started Guide Version 1 2 3 20131213 f t Your systems Working as one 2005 2013 Real Time Innovations Inc All rights reserved Printed in U S A First printing December 2013 Trademarks Real Time Innovations RTL and Connext are trademarks or registered trademarks of Real Time Innovations Inc All other trademarks used in this document are the property of their respective owners Copy and Use Restrictions No part of this publication may be reproduced stored in a retrieval system or transmitted in any form including electronic mechanical photocopy and facsimile without the prior written permission of Real Time Innovations Inc RTI Connext software is furnished under and subject to the RTI software license agreement The software may be used or copied only under the terms of the license agreement Wireshark is Open Source software released under the terms of the GNU General Public License version 2 as published by the Free Software Foundation Technical Support Real Time Innovations Inc 232 E Java Drive Sunnyvale CA 94089 Phone 408 990 7444 Email supportGrti com Website https support rti com Contents ME alicele 191 1 ME T TP T 1 1 11 Available Documentation enie eei a e a a e E e E Ee e e a 1 2 1 2 Re ding Guide rre ree ene er ee eate o ELA e cd iei ete e t iae 1 3 E3 Howto Get Supp
19. cai feeerab eei dee n e dede 6 2 6 3 Providing Information to RTI Support esse sees eee eee eee 6 4 iii Chapter 1 Introduction Wireshark is a network packet analyzer that supports many network protocols including Real Time Publish Subscribe RTPS the wire protocol used by RTI Connext formerly RTI Data Dis tribution Service middleware Wireshark can be used to capture and analyze RTPS packets from Connext applications It sup ports RTPS 2 1 and lower and is specifically tailored to make RTPS packet analysis easier by including LI A set of predefined filters to quickly select different groups of packets from the RTPS pro tocol J A column in the Packet List that shows the GUID Prefix for each RTPS packet This value uniquely identifies a DomainParticipant within a Domain L Coloring rules that highlight important RTPS packets Packets not strictly related to Con next traffic are grayed out Network packet and traffic analyzers are used during application development and distributed system configuration to monitor the packets over the network You can use filters to capture spe cific types of packets then analyze the captured packets This manual will help you use Wireshark to analyze RTPS packets This analysis will give you information on two levels J A high level look at the RTPS submessages that are flowing between your Connext appli cations LI A detailed look at the contents of individual packets Wire
20. ed in the latest RTPS 2 spec ification The values of traffic nature correspond to the following kinds of traffic LJ 10 Meta Traffic Unicast J 11 User Traffic Unicast LJ 0 Meta Traffic Multicast LJ 1 User Traffic Multicast Important The packet decoder assumes the applications are using the default value for the receive_port Therefore it is important to note that if the receive_port has been explicitly changed in the locators receive_port field of the TransportUnicast or TransportMulticast QosPolicy then the domain id participant idx and traffic nature values will be calculated incorrectly in this case these three fields should not be used in display filters nor assumed to be correct in the decoded packet view We expect this changing of the receive port to be a rare occurrence Color Coding Packets Wireshark allows you to display packets in different colors Coloring rules are based on the same criteria used to create display filters described in Section 5 2 1 For instance you can show dis covery related packets in blue and user data packets in green Unlike display filters coloring rules do not hide captured packets Wireshark includes RTPS related coloring rules that are automatically enabled they are listed in Table 5 3 You can turn them off change the colors or edit them in other ways See the Wireshark User s Guide for details To understand the elements in the strings refer to the Real Time Publish S
21. er A display filter only shows packets that match a certain set of criteria You may want to start by showing only RTPS packets Wireshark provides a display filter for just this purpose There are also predefined filters for displaying just discovery meta traffic or just user data traffic 5 3 Displaying Packets To display RTPS packets only 1 2 3 In the main window clear anything you have in the filter text box with the Clear button then click the Filter button Select the preconfigured filter named Only RTPS packets Click OK to close the Filter Expression window Figure 5 2 Selecting a Display Filter 1 Select a Only meta traffic predefined filter r Wireshark Display Filter Filter Only user traffic Only RTPS packets Only NDDSPING packets Packets with topic info Data Writer Announce Data Reader Announce Participant Announce Data Writer Destruction Data Reader Destruction Dartirinant Nectriictinn Properties Filter name Only RTPS packets Filter string rtps2 amp amp licmp 2 Click OK As another example let s look at how to display only RTPS packets that contain HEARTBEAT submessages To display HEARTBEAT packets only 1 N Oo Ug B Q Clear anything you have in the filter text box with the Clear button then click the Expression button In the new Filter Expression window scroll down in the Field name list until you see R
22. f Wireshark includes two files that contain packets captured from Connext 4 5f applications userDataTrace pkt A short trace of captured user data packets This shows the flow of packets in an established system after all the objects have discovered each other Analyzing Packets from Connext Applications 5 3 1 discoveryTrace pkt A longer trace of the packets sent during the discovery startup process The location of the sample files depends on your operating system Linux usr share wireshark I Solaris usr local share wireshark LJ Windows lt WiresharkHOME gt rti where lt WiresharkHOME gt is where Wireshark is installed By looking at these sample files you will learn how to 1 Load a captured sequence of packets from a file I Understand the flow of RTPS messages by looking at a sample sequence 1 View the contents of individual RTPS packets Analyzing the User Data Sample Trace Use the File Open command to open the file userDataTrace pkt see Section 5 3 for its loca tion The sample file contains a sequence of RTPS packets that illustrate the protocol when two appli cations use reliable communications to send receive data This scenario involves two hosts each running a Connext application J Host 1 10 20 1 86 is running a Connext publishing application Appl l Host 2 10 10 30 100 is running a Connext subscribing application App2 I The QoS for the writer and the reader have been set up t
23. ing both INFO TS and DATA 1 submessages Packet has sequence number 2 expand the protocol tree in Appl App2 the Packet Details pane and check the writerSeqNumber value as seen in Figure 5 8 2 HEARTBEAT from writer to reader ACKNACK to acknowledge all data packets up to but not including App1 lt App2 3 sequence number 3 expand the protocol tree in the Packet Details pane and check the readerSNState bitmapBase value 4 Another data packet sequence number 3 App1 App2 5 HEARTBEAT from writer to reader App1 lt App2 6 ACKNACK to acknowledge packet 4 7 Another data packet sequence number 4 App1 App2 8 HEARTBEAT from writer to reader App1 lt App2 9 ACKNACK to acknowledge packet 7 5 10 Analyzing Packets from Connext Applications Figure 5 7 User Data Sample Packet Flow App App 2 Analyzing Packets from Connext Applications Figure 5 8 Examining Packet Details Select a packet in the Packet List a 0 10 20 100 INFO_TS DATA 2 2 000907 10 20 1 86 10 10 30 100 RTPS2 INFO_DST HEARTBEAT 3 2 001181 10 10 30 100 10 20 1 86 RTPS2 INFO_DST ACKNACK 4 4 000938 10 20 1 86 10 10 30 100 RTPS2 INFO_TS DATA 5 5 003878 10 20 1 86 10 10 30 100 RTPS2 INFO_DST HEARTBEAT 6 5 004171 10 10 30 100 10 20 1 86 RTPS2 INFO_DST ACKNACK 7 8 001939 10 20 1 86 10 10 30 100 RTPS2 INFO_TS DATA 8 8 005850 10 20 1 86 10 10 30 100 RTPS2 INFO_DST HEARTBEAT 9 8 006104 10 10 30 100 10 20 1 86
24. les of captured RTPS packets During this process you will need to reference the Real Time Publish Subscribe Wire Protocol Specification I Read Chapter 6 Practical Uses with RTI Applications for ideas on how to use Wireshark during Connext application development l Consult the Wireshark online help and user s guide for information on other features How to Get Support Technical support for Wireshark is provided by RTI send e mail to support rti com Wireshark is an open source product For information about Wireshark support please visit www wireshark org 1 3 Chapter 2 Installation 2 1 2 2 2 3 Wireshark is automatically installed by the RTI Connext Professional Edition installer Use the installation instructions in this chapter only if you are installing Wireshark independently not through the Connext Professional Edition installer To install Wireshark you need to login as super user on Linux and Solaris systems or as admin istrator on Windows systems You will also need super user administrator access to capture packets With normal user access you will be able to run Wireshark but only to view previously saved capture files Before Installation If you have Ethereal Wireshark or RTI Protocol Analyzer with Wireshark installed we highly rec ommend that you remove them before installing RTI s distribution of Wireshark See Uninstall ing Wireshark Section 2 6 Installing Wireshark on Window
25. m the writer participant dolci HEARTBEATs telling the reader participant how many readers 0 and writers 1 P PP it has The reader participant will know from this that it has to get a meta DATA 2324 from the writer Note to be precise each meta DATA reflects a change to the state of the writer or reader The number of writer samples would increase if the writer was changed or deleted 25 Writer participant packet 22 for reader participant index 1 was not reachable because the reader participant was created with participant id 0 26 27 ACKNACKs telling the reader participant that builtin discovery readers for publications and subscriptions are created Reader participant begins to announce its builtin discovery endpoints after 28 having received the writer participant s announcements ACKNACK from the reader participant s builtin participant liveliness reader 29 30 Re announcements of reader participant info triggered by receiving the writer announcements Appl lt App2 31 35 Initial HEARTBEATs and ACKNACKs from the reader participant s builtin discovery endpoints indicating it has one reader and no writers 36 ACKNACK in response to HEARTBEAT packet 24 requesting that the writer participant s builtin publication writer resend the meta DATA for its writer 37 38 HEARTBEATs sent in response to writer ACKNACKs announcing that the reader participant has one reader and no writers App1 App2 39 Initial HEARTBEAT from participant liveliness wri
26. n about where to reply to the entities that appear in subsequent INFO_REPLY2 submessages The list of locators provided allows for any transport type and can accommodate 16 byte addresses INFO TS Provides a source timestamp for subsequent Entity submessages NACK FRAG Provides information on the state of a Reader to a Writer Contains information regarding the value of an application Data object that cannot be referenced by a key NOKEY DATA In Connext 4 5 and higher as well as RTI Data Distribution Service 4 2e and higher this submessage is not used NOKEY DATA FRAG Contains a fragment of information regarding the value of an application data object that cannot be referenced by a key In Connext 4 5 and higher as well as RTI Data Distribution Service 4 2e and higher this submessage is not used PAD Provides padding to meet any desired memory alignment requirements a INFO TS is an abbreviation for INFOTIMESTAMP 5 2 1 Displaying Packets Wireshark has two features that make it easy to focus on packets with a particular set of values L Display filters limit the display to just packets that meet a set of criteria See Section 52 1 I Coloring rules allow you to color code packets based on a set of criteria so they stand out more in the full packet list See Section 5 2 2 For more information on filters and colors select Help Wireshark Online User s Guide from the menubar Using a Display Filt
27. n on Debian packages please see http packages debian org 1 Login as super user 2 Enter cd location of distribution files 3 Enter dpkg i Wireshark common version architecture deb 4 To install Wireshark enter dpkg i Wireshark version architecture deb 5 To install Tshark enter dpkg i Tshark version architecture deb Installing Wireshark on Solaris Systems Before Installation M Make sure you have installed the required packages listed in Section 1 1 in the Release Notes Make sure you have modified the font cache configuration file and rebuilt the font cache see Section 1 1 1 in the Release Notes L Make sure you have root privileges Installation 1 cd location of distribution file 2 gunzip Wireshark version architecture gz 3 pkgadd d Wireshark lt version gt lt architecture gt Uninstalling Wireshark To uninstall from a Linux Red Hat or SUSE system while logged in as root enter rpm e wireshark To uninstall from a Linux Debian system while logged in as root a To uninstall the common package dpkg r wireshark wireshark common 2 2 Uninstalling Wireshark b To uninstall Wireshark dpkg r wireshark common wireshark c To uninstall Tshark dpkg r wireshark common tshark LJ To uninstall from a Solaris system while logged in as root enter pkgrm wireshark LJ To uninstall from a Windows system From the Start menu select Co
28. ntrol Panel Add Remove Programs or Programs and Features Wireshark 2 3 Chapter 3 Starting Wireshark Important To capture packets from the network you must run Wireshark as root administrator On Linux systems usr bin wireshark amp On Solaris systems usr local bin wireshark amp On Windows systems Use the Start menu to select Wireshark Alternatively on Linux and Solaris systems to capture with tshark the terminal based version of Wireshark run tshark from the same paths as above On Windows systems you can start tshark from installation directory gt tshark 3 1 Chapter 4 Capturing RTPS Packets This chapter describes how to capture RTPS packets that are sent across a network After captur ing packets use the information in Chapter 5 to analyze them Wireshark will automatically capture all RTPS packets from the wire You can create additional filters to refine the scope of your captures For example you can create filters to capture packets from specific nodes addresses ports protocols etc This chapter pro vides basic instructions on using capture filters and a few examples For more information see the Wireshark User s Guide or online documentation To capture all types of packets while running a Connext application 1 Login as super user on Linux Solaris systems or administrator on Windows systems 2 Start Wireshark 3 Select Capture Options from the menubar Figure 4 1
29. o use Reliable communications I Appl writes user data every 4 seconds To create the sample capture file Wireshark started capturing packets on the subscribing host after the discovery process completed using the following capture filter rtps2 amp amp ip src 10 10 30 100 ip dst 10 10 30 100 Figure 5 6 shows the packets captured by Wireshark which includes three types of RTPS packets Data from the writer to the reader IJ Acknowledgements from the reader to the writer Heartbeats sent regularly from the writer to the reader Table 5 4 and Figure 5 7 describe the trace shown in Figure 5 6 Figure 5 6 User Data Sample Packets Destination Protocol GUID prefix 1 0 000000 10 10 30 100 INFO_TS DATA 2 2 000907 10 20 1 86 10 10 30 100 RTPS2 INFO_DST HEARTBEAT 3 2 001181 10 10 30 100 10 20 1 86 RTPS2 INFO_DST ACKNACK 4 4 000938 10 20 1 86 10 10 30 100 RTPS2 INFO_TS DATA 5 5 003878 10 20 1 86 10 10 30 100 RTPS2 INFO_DST HEARTBEAT 6 5 004171 10 10 30 100 10 20 1 86 RTPS2 INFO_DST ACKNACK 7 8 001939 10 20 1 86 10 10 30 100 RTPS2 INFO_TS DATA 8 8 005850 10 20 1 86 10 10 30 100 RTPS2 INFO_DST HEARTBEAT 9 8 006104 10 10 30 100 10 20 1 86 RTPS2 INFO_DST ACKNACK 5 9 Analyzing Packets from Connext Applications Table 5 4 Analysis of User Data Sample Trace Direction Packet Description Data packet sent to the reader contain
30. orts ass dead ve He dde toe ndi eub te bond due te bendi 1 3 AN Is mee Dd 2 1 2 1 Before Installation repete tet en idem fee t tee iR e e dua 2 1 2 2 Installing Wireshark on Windows Systems sse eene eene nennen 2 1 23 Installing Wireshark on Linux Red Hat and SUSE Systems sss 2 1 24 Installing Wireshark on Linux Debian Systems sese eee nenne 2 2 25 Installing Wireshark on Solaris Systema sees essere 2 2 2 6 Uninstalling Wireshatk aetate te o deret eer etae et ip ee Pepe ede iere 2 2 leere qe iita iaia du diania 3 1 Capturing RIPS PACKETS RR 4 1 Analyzing RTPS Packels etri nieo th thai p SEES CERE ERE navadna soagn OE UKI Seek PUN iat 5 1 bib RTPSSubmessage Types rie etie eee ee etn fe eee 5 1 5 2 Displaying T ote e RUSRUHI Ute iae tei een eres 5 3 5 2 1 Using a Display Filters sue eee eee die em ee b ee ente 5 3 5 2 2 Color Coding Packets eee te hetero dot eet dioe iter dee ide 5 7 5 3 Analyzing Packets from Connext Applications esses eee eene nnn 5 8 5 3 4 Analyzing the User Data Sample Trace eee eee enn 5 9 5 3 2 Analyzing the Discovery Data Sample Trace sss essen 5 13 6 Practical Uses with RTI Applications eeeeeeee serrer eene enne 6 1 6 1 Debugging Discovery Problems sse eene eee nnne nnn nnne enne ea 6 1 6 2 Vis alizing Yo r Systeme teer indtusidipiee ad tec
31. packet GUID Prefix rtps appld App ID component of the packet GUID Prefix rtps appld instanceld Instance ID of the App Id component of the packet GUID Prefix rtps appld appKind App Kind of the App Id component of the packet GUID Prefix Submessage specific fields rtps sm id Submessage type see Table 5 1 rtps sm flags Byte representing the submessage flags rtps sm octectsToTextHeader Value of the octetsToNextHeader from the submessage header rtps sm guidPrefix Generic GUID Prefix that appears inside a submessage this does not match the GUID Prefix of the packet header rtps sm guidPrefix hostId Host ID component of the submessage GUID Prefix rtps sm guidPrefix appId App ID component of the submessage GUID Prefix rtps sm guidPrefix appld instanceld Instanceld component of the App ID of the submessage GUID Prefix rtps sm guidPrefix appId appKind Object kind component of the App ID of the submessage GUID Prefix rtps sm entityId Object entity ID as it appear in a DATA submessage keyHashSuffix rtps sm entityId entityKey entityKey field of the object entity ID rtps sm entityId entityKind entityKind field of the object entity ID rtps sm rdentityId Reader entity ID as it appear in a submessage rtps sm rdentityId entityKey entityKey field of the reader entity ID rtps sm rdentityId entityKind entityKind field of the reader entity ID
32. packets are generated 5 13 Analyzing Packets from Connext Applications Figure 5 9 Discovery Data Sample File W 00 74 OY un wn 0 000045 0 000130 0 000161 0 008788 0 008801 0 009079 0 009098 0 017908 0 017923 0 018227 0 018254 5 423355 5 423415 5 423977 5 424000 5 427251 5 427271 5 441956 5 446546 5 446635 5 446664 5 446779 5 446911 5 446963 5 447070 5 447220 5 447630 5 447871 5 447886 5 447909 5 448129 5 448144 5 448154 5 448374 5 448588 5 448606 5 448617 5 449305 5 449490 5 457424 5 457532 5 457603 5 457623 5 457695 5 457796 5 457948 5 458131 5 458150 5 460151 8 037246 12 037962 16 037869 10 10 100 65 10 10 100 65 10 10 30 100 10 10 30 100 10 10 100 65 10 10 100 65 10 10 30 100 10 10 30 100 10 10 100 65 10 10 100 65 10 10 30 100 10 10 30 100 10 10 30 100 10 10 30 100 10 10 30 100 10 10 30 100 10 10 30 100 10 10 30 100 10 10 100 65 10 10 100 65 10 10 100 65 10 10 100 65 10 10 100 65 10 10 100 65 10 10 30 100 10 10 100 65 10 10 100 65 10 10 30 100 10 10 30 100 10 10 30 100 10 10 30 100 10 10 30 100 10 10 30 100 10 10 30 100 10 10 30 100 10 10 30 100 10 10 30 100 10 10 30 100 10 10 100 65 10 10 30 100 10 10 100 65 10 10 100 65 10 10 100 65 10 10 30 100 10 10 100 65 10 10 100 65 10 10 30 100 10 10 100 65 10 10 30 100 10 10 100 65 10 10 100 65 10 10 100 65 10 10 100 65 20 100 10 10 30 100 10 10 100
33. re Session l Select which Eee Capture optons oo em Network m Interface to use from this pull Interface Marvell Gigabit Ethernet Controller Device NPF_ B4D2A077 DF1C 4BDE B509 8D016C289DC5 lz down selection IP address 192 168 2 5 box Link layer header type Ethernet gt Buffer size 1 megabyte s Wireless Settings V Capture packets in promiscuous mode 7 Limit each packet to 68 bytes 2 Optionally Capture Filter B enter a capture filter Capture File s Display Options Fle V Update list of packets in real time 7 Use multiple files 3 Consider Next fle ever 1 nini V Automatic scrolling in live capture turning Next file ever 1 minute s BE ide capture info dialog these off R 2 3 see Note Ring buffer with 2 files Name Resolution top capture after 1 file s Stop Capture V Enable MAC name resolution El after packet s E Enable network name resolution after IF after instet V Enable transport name resolution Help Start Cancel 4 Start capturing packets computer Therefore we suggest that you apply a capture filter so that Wireshark only captures the type of packets you want to see Simply enter a valid capture filter string in the Capture Filter box see Figure 4 1 before you press Capture Table 4 1 provides some examples Table 4 1 Example Capture Filters To Capture Enter Capture
34. rk card on the sniffing machine itself dropped them 6 2 Visualizing Your System Figure 6 1 Figure 6 2 UDP Conversations UDP Conversations Address A eS Ca Packets A gt B A gt B Packets A lt B Bytes 239 255 255 250 1900 ash 1024 5304 0 5304 mammothDHCP100198 6001 255 255 255 255 6001 A 6672 12 um d 0 mammothDHCP10074 34063 10 10 1 160 53 8 966 4 353 4 613 targets 520 10 10 255 255 520 6 456 6 456 0 0 5 e 4 79 0 0 4 792 235 10 9 9 7400 ety 26 3194 4 792 0 0 4 792 235 10 9 9 7400 ety 32 3197 4 792 0 0 4 792 10 10 1 192 1023 mammothDHCP10074 874 4 336 2 144 2 192 235 10 9 9 7400 ety 32 3198 4 792 0 0 4 792 235 10 9 9 7400 ety 26 3195 4 792 0 0 4 792 rushmore 138 10 10 255 255 138 3 798 3 798 0 0 nasl 137 10 10 255 255 137 3 282 3 282 0 0 mammothDHCP100162 137 10 10 255 255 137 3 282 3 282 0 0 mammothDHCP100165 137 10 10 255 255 137 3 282 3 282 0 0 1220 10 310 Or rr 120 3 DOA Ld ANA n n 1 O Graph 10 5 Teb ge e R 2 I T T E o T Tq Ue oe T T WV d T T W ew 4 T W c 1 T T 0 10 0s 15 0s 20 0s 25 0s 30 0s 35 0s gt X Axis Line Y Tick mena O 1sec gt dine v Pixels per tick Line Y Y Axis zl inm X Unit Packets Tick J lee me Y Frame 25957 Y Linux cooked mode capture 100 00 128 25957 0 005 0 0 0 000 Y Internet Protocol 100 00 128 25957 0 005 0 0 0 000 User Datagram Protocol 100 00 128 25957 0 005 0 0
35. s Systems 1 Right click on the distribution file Wireshark lt version gt Win32 exe and select Run as Administrator This will install Wireshark and Tshark a terminal based non GUI version of Wireshark in the same path The default installation path is C Program Files Wireshark 2 Wireshark requires WinPcap 4 1 If WinPcap 4 1 is not already installed it will be installed with Wireshark If it is already installed you will be asked if you want to re install Win Pcap or skip the WinPcap installation You can safely skip re installing WinPcap Installing Wireshark on Linux Red Hat and SUSE Systems Install Wireshark using the Red Hat Package Manager RPM 1 Login as super user 2 cd lt location of the distribution file gt 3 rpm i Wireshark lt version gt lt architecture gt rpm For more information on installing RPMs please see http www rpm org 2 1 Installing Wireshark on Linux Debian Systems 2 4 2 5 2 6 Installing Wireshark on Linux Debian Systems Before Installation J Make sure you have installed the required packages listed in Section 1 2 in the Release Notes Installation Note that at least two packages need to be installed a common package and either a Wireshark or Tshark package The Wireshark package installs the GUI version while the Tshark package installs a terminal based non GUI version You can install either one of these packages or both For more informatio
36. s use best effort communications to send receive data This scenario involves two hosts each running one Connext application J Host 1 10 10 100 65 is running a Connext publishing application Appl J Host 2 10 10 30 100 is running a Connext subscribing application App2 1 Both applications have a maximum participant index of 1 and have each other in their initial peer list LJ All but one QoS are at default values this default includes the use of automatic discovery via the default UDPv4 transport The one non default QoS is having both applications initial participant announcements set to 1 as this reduces the number of redundant announcements in the example trace Wireshark was set up to start capturing packets before either application was started The publish ing application was started first followed about 6 seconds later by the subscribing application Figure 5 9 shows the packets captured by Wireshark Let s walk through the RTPS packets to understand what occurred in this sequence Table 5 5 describes what happened non RTPS packets are omitted In the table the term meta DATA refers to DATA packets containing meta discovery data as opposed to user data Table 5 5 Analysis of Sample File s Packets Direction Packet Description When the writer participant starts Connext announces the creation of a new par ticipant to all potential participants in the initial peer list Potential participants are
37. shark s main window makes it easy to see both views Figure 1 1 shows the main window and points out some important features 1 1 Available Documentation Figure 1 1 1 1 Wireshark s Main Window GUID Prefix Column only available in RTI s distribution of Wireshark Eile Edit View Go Capture Analyze Statistics Help Swaine ae eas eee TM x A 17 0 019035 10 10 100 14 23 TES Ox0a0a640 Or 8880 DATA Packet 0 020581 10 100 1392 1 Ox0adaed0e OXLSSGO ACKNACK 20 0 020856 10 10 100 14 K P RTPS OxQa0a640e 0x18880 ACKNACK sequence 21 0 021401 10 10 100 14 192 1 RTPS 0x0a0a640e 0x18880 DATA we i5 with 22 0 021616 10 10 100 14 7 PE RTPS 0x0a0a640e Ox18880 DATA n 23 0 022254 10 10 100 14 k adis RTPS Ox0a0a640e Ox18880 DATA 75 automatic 24 0 140703 10 10 100 14 192 1 RTPS 0x0a0a640e Ox18880 DATA o color 25 2 711920 10 10 100 14 PE RTPS Ox0a0a640e Ox18880 HEARTBEAT NX 26 2 992846 10 10 100 14 PE RTPS Ox0a0a640e Ox18880 HEARTBEAT O coding of 27 3 022182 10 10 100 14 thiet RTPS Ox0a0a640e Ox18880 NOKEY DATA O RTPS 28 4 022386 10 10 100 14 K si RTPS OxOa0a640e Ox18880 NOKEY DATA a 29 5 022576 10 10 100 14 K sds RTPS 0x0a0a640e 0x18880 NOKEY DATA packets 30 5 713828 10 10 100 14 192 1 RTPS 0x0a0a640e Ox18880 HEARTBEAT 31 5 993371 10 10 100 14 E Eus RTPS OxOa0a640e Ox18880 HEARTBEAT 32 5 993520 10 10 100 14 x Pp RTPS OxO0a0a640e Ox18880 ACKNA
38. ter of no samples written App1 lt App2 40 ACKNACK from participant liveliness reader of no samples received ACKNACK from writer participant for reader participant to resend the meta 41 Appl App2 DATA for its reader 42 43 Further HEARTBEATS from the reader participant ApplcApp2 44 Pan meta DATA about the reader sent in response to the ACKNACK of packet A resent meta DATA about the writer sent in response to the ACKNACK of App1 App2 45 packet 36 Appl lt App2 46 49 ACKNACKs that all resent DATA was received successfully 50 PING from the application writer to the application reader s locator App1 App2 eae 51 53 Writer finally sends user DATA to the reader 5 15 Chapter 6 Practical Uses with RTI Applications 6 1 This chapter offers a few suggestions on how Wireshark can be used during Connext application development Ll Debugging Discovery Problems Section 6 1 J Visualizing Your System Section 6 2 m Providing Information to RTI Support Section 6 3 Debugging Discovery Problems While many object discovery problems are difficult to diagnose others are quite obvious once you use the right diagnostic tools By inspecting all RTPS packets with Wireshark you may be able to narrow the problem down to one of the following The participants are not discovering each other In this case you will see periodic send ing of DATA packets but no response from the other host that is not being discovered The
39. tes pdf for system requirements installation instructions and other important information LJ RTI Connext Core Libraries and Utilities User s Manual This document provides details on the Connext API and describes how RTPS packets are used by Connext based applica tions In particular you should review the Discovery chapter Open lt NDDSHOME gt doc pdf RTI CoreLibrariesAndUtilities UsersManual pdf where lt NDDSHOME gt is where you installed Connext L RTPS Specification Please see http www omg org spec DDSI 2 1 1 2 Reading Guide 1 2 1 3 I Wireshark online help There is extensive online help included with Wireshark Select Help Contents from the menubar for a detailed user s guide in HTML format J Wireshark User s Guide This PDF document describes how to use Wireshark s features It is not included in the installation but can be downloaded from Wireshark s website www wireshark org docs Note that it may pertain to a slightly different version of Wireshark Reading Guide We suggest that you read the documentation in the following order J Read this chapter to become familiar with the system requirements L Read the RTI Wireshark Release Notes Follow the steps in Chapter 2 Installation J Read Chapter 4 Capturing RTPS Packets for a quick overview of how to capture RTPS packets J Read Chapter 5 Analyzing RTPS Packets to learn how to analyze each type of RTPS packet by looking at sample fi
40. their liveliness automatically or manually within the declared duration A classic symp tom of communication ceasing due to a liveliness expiration is that a participant stops sending its periodic participant DATA packet See the RTI Core Libraries and Utilities User s Manual or online documentation for information about the Liveliness QosPolicy NOTE Connext can log more detailed information about what it is doing at higher ver bosity settings See the RTI Core Libraries and Utilities User s Manual s Troubleshooting chapter for more information on setting verbosity Visualizing Your System Once your applications are communicating tuning Connext to maximize performance may require an in depth understanding of your network A visual understanding of Connext network usage is very valuable for system tuning For example you may be sending data as fast as Connext will allow and wonder why the reader cannot keep up Wireshark itself offers many statistical analysis tools under the Statistics menu As Figures 6 1 through 6 3 show you can see how many RTPS packets are being sent what por tion of total network bandwidth RTPS packets are taking up which hosts are talking to others and how much bandwidth is being used to do so In our sending too fast example you may find that the RTPS packets are being dropped at a host with a relatively slow reader In some extreme cases even Wireshark may not see all the packets sent because the netwo
41. ubscribe Wire Protocol Specification see Available Documentation Section 1 1 Figure 5 5 shows a sample display To create a new coloring rule 1 Select View Coloring Rules then click the New button to open an Edit Color Filter window 2 Enter a name for the color filter such as HeartBeatPackets 5 7 Analyzing Packets from Connext Applications Figure 5 5 Using Coloring Rules Table 5 3 5 3 ZU U UZUS356 IU lIU lUU I4 Z39 192 1l 2 RTPS UxUdUao4Ue UXISSSU ACKNACK 21 0 021401 10 10 100 14 239 192 1 2 RTPS OxO0a0a640e Ox18880 DATA w4 22 0 021616 10 10 100 14 239 192 1 2 RTPS OxOaQ0a640e QOx18880 DATA 23 0 022254 10 10 100 14 239 192 1 2 RTPS OxOaQ0a640e Ox18880 DATA 24 0 140703 10 10 100 14 239 192 1 2 RTPS OxOa0a640e Ox18880 DATA 25 2 711920 10 10 100 14 239 192 1 2 RTPS OxOaO0a640e Qx18880 HEARTBEAT 26 2 992846 10 10 100 14 239 192 1 2 RTPS OxOaQ0a640e Qx18880 HEARTBEAT 27 3 022182 10 10 100 14 239 192 1 2 RTPS Ox0a0a640e Qx18880 NOKEY DATA 28 4 022386 10 10 100 14 239 192 1 2 RTPS Ox0a0a640e Qx18880 NOKEY DATA 29 5 022576 10 10 100 14 239 192 1 2 RTPS OxOa0a640e Qx18880 NOKEY DATA 30 5 713828 10 10 100 14 239 192 1 2 RTPS OxOa0a640e Ox18880 HEARTBEAT 31 5 993371 10 10 100 14 239 192 1 2 RTPS OxQada640e Ox18880 HEARTBEAT 32 5 993520 10 10 100 14 239 192 1 2 RTPS OxQa0a640e Ox18880 ACKNACK 33 5 993643 10 10 100 14 239 192 1 2 RTPS OxOada640e QOx18880 ACKNACK Coloring rules make is easy to see different t
42. ypes of submessages Default Coloring Rules Coloring Rule String RTI DDSPing green udp 16 23 rtiddsping User traffic red rtps sm wrEntityId entityKind 0x02 rtps sm wrEntityId entityKind 0x03 rtps2 sm wrEntityId entityKind 0x02 rtps2 sm wrEntityId entityKind 0x03 Meta traffic blue rtps sm wrEntityId entityKind 0xc2 rtps sm wrEntityId entityKind 0xc3 rtps2 sm wrEntityId entityKind 0xc2 rtps2 sm wrEntityId entityKind 0xc3 Non RTPS traffic gray Irtps amp amp rtps2 3 Enter a color filter expression using the same syntax as for a display filter If you need help click the Expression button For examples see Table 5 3 Select foreground text and background colors for packets that match the filter expres sion Tip To select a color click in the color selection triangle use the colored circle to quickly change the contents of the triangle Click OK to close the Edit Color Filter window Click Apply in the Coloring Rules window Tip The order of the coloring rules is important The rules are applied in the order in which they appear in the dialog box So if there are two rules that are true for the same packet the first will be used and the second one ignored You can use the Up and Down buttons on the dialog to change the order of the rules Analyzing Packets from Connext Applications RIT s distribution o
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