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Transport Protocols on IP MulticastingTransport Protocols on IP Multicasting

Chao Li Thomas Su Cheng LuChao Li Thomas Su Cheng Lu {clij, tmsu, clu}@cs.sfu.ca {clij, tmsu, clu}@cs.sfu.ca School of Computing Science, School of Computing Science, Simon Fraser University Simon Fraser University

CMPT885 High-Performance Network

Final Project Presentation

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RoadmapRoadmap

•• IntroductionIntroduction•• Implementation DetailsImplementation Details

–– Centralized ApproachCentralized Approach–– Scalable Reliable MulticastScalable Reliable Multicast–– Tree Based Reliable MulticastTree Based Reliable Multicast

•• DiscussionDiscussion•• ReferencesReferences

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Introduction of Our ProjectIntroduction of Our Project

•• Why we need Why we need ““multicastmulticast””??•• Why we need Why we need ““multicast transportmulticast transport

protocolprotocol””??•• What we will do in our project?What we will do in our project?

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Introduction of MulticastIntroduction of Multicast

•• Unicast Vs MulticastUnicast Vs Multicast–– Multiple copy Vs single copyMultiple copy Vs single copy

•• Datalink Layer Support for MulticastDatalink Layer Support for Multicast•• Network Layer Support for MulticastNetwork Layer Support for Multicast

–– Multicast routingMulticast routing–– Group membership managementGroup membership management–– Group network addressingGroup network addressing

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Multicast Transport ProtocolsMulticast Transport Protocols

•• Why not just run TCP over Multicast?Why not just run TCP over Multicast?•• Multicast Transport ProtocolsMulticast Transport Protocols

–– Centralized ApproachCentralized Approach–– Unstructured ApproachUnstructured Approach

•• Scalable Reliable Multicast (SRM)Scalable Reliable Multicast (SRM)

–– Distributed ApproachDistributed Approach•• Tree-based Multicast Transport ProtocolsTree-based Multicast Transport Protocols

(TMTP)(TMTP)

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Centralized MulticastCentralized Multicast

•• FeatureFeature–– Rely on a central siteRely on a central site–– Negative acknowledgment (NACK or NAK)Negative acknowledgment (NACK or NAK)–– SlottingSlotting

•• AdvantagesAdvantages–– Simplicity and ease of implementionSimplicity and ease of implemention

•• DisadvantagesDisadvantages

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SRM- Scalable ReliableSRM- Scalable ReliableMulticastMulticast

•• Requires only basic IP delivery modelRequires only basic IP delivery model•• Every member is responsible for lossEvery member is responsible for loss

recoveryrecovery•• Allow to a wide range of group sizeAllow to a wide range of group size

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SRM- Scalable ReliableSRM- Scalable ReliableMulticastMulticast

•• Three types of messagesThree types of messages–– Session messageSession message–– Request messageRequest message–– Repair messageRepair message

Messages are multicast to the entireMessages are multicast to the entiregroupgroup

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SRM- Scalable ReliableSRM- Scalable ReliableMulticastMulticast

•• Session messagesSession messages–– Report the highest sequence # receivedReport the highest sequence # received

by every memberby every member–– Provide information for sender/receiversProvide information for sender/receivers

(status, # of participants, etc.)(status, # of participants, etc.)–– Estimate host-to-host distance (neededEstimate host-to-host distance (needed

for repair)for repair)

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SRM- Scalable ReliableSRM- Scalable ReliableMulticastMulticast

•• Request messagesRequest messages–– loss detected when there is a gap inloss detected when there is a gap in

the sequence #the sequence #–– A host wait a random time beforeA host wait a random time before

multicast the request to the groupmulticast the request to the group–– Any host that has a copy of theAny host that has a copy of the

requested data can answerrequested data can answer

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SRM- Scalable ReliableSRM- Scalable ReliableMulticastMulticast

•• Repair messagesRepair messages–– Wait a random time before multicast theWait a random time before multicast the

repair packet to the grouprepair packet to the group

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Simulation Environment Simulation Environment Topology(from[8][9]) Topology(from[8][9])

Source Campus Network

Campus Network

3Mbit/s Link1.5Mbit/s Link

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Configuration DetailsConfiguration Details

TCP/FTPTCP/FTPSenders/receivers spared all overSenders/receivers spared all overSession interval 10sSession interval 10sburst size 80,000 byteburst size 80,000 byte

HTTPHTTPEach campus network has oneEach campus network has oneweb server, other nodes areweb server, other nodes areclientsclients# of Sessions 800# of Sessions 800# of page components 3# of page components 3page component size 12KBpage component size 12KB

BackgrouBackground trafficnd traffic

The credit goes to Velibor Markovski

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More Configuration DetailsMore Configuration Details

CBR traffic (0.04s)CBR traffic (0.04s)1 sender and 9 receivers1 sender and 9 receivers512 packet size512 packet sizeStart at 10s for 200sec.Start at 10s for 200sec.Session message frequencySession message frequency2s(SRM default)2s(SRM default)

MulticastMulticasttraffictraffic

More experiment data will be collected on

-Larger group size

-Star war Trace

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Snapshot(topology)Snapshot(topology)

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Snapshot(router)Snapshot(router)

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Simulation Results(RequestSimulation Results(Requestdelay)delay)

Comparision of Request Delay

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Receiver Node

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CentralizedMulticast

SRM

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Simulation Results(RequestSimulation Results(Requestduplicate)duplicate)

Camparision of Request Duplicate

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Centralized Multicast

SRM

Tree-based MulticastTree-based MulticastTransport Protocol (TMTP)Transport Protocol (TMTP)

We are Implementing this protocolWe are Implementing this protocolin ns2 using C++ and in ns2 using C++ and TClTCl

TMTPTMTP –– key featureskey features

•• It exploits the It exploits the IP multicastIP multicast for packet routing and for packet routing anddelivery.delivery.

•• It dynamically organize the participants intoIt dynamically organize the participants intohierarchical control treehierarchical control tree..

•• It achieves scalable reliable multicast viaIt achieves scalable reliable multicast viahierarchical control tree used for hierarchical control tree used for flow and errorflow and errorcontrolcontrol..

TMTP TMTP –– hierarchical control hierarchical controltreetree

•• It organizes the participantsIt organizes the participantsinto a hierarchical domain.into a hierarchical domain.

•• A domain manager(DM) actsA domain manager(DM) actsas a representative of eachas a representative of eachdomain.domain.

•• Every DM performs two rolesEvery DM performs two rolesfor the responsibility forfor the responsibility forreliability reliability ––

inter-domain and inter-domain and intra-domain . intra-domain .

TMTP TMTP ––control treecontrol treemanagementmanagement

•• The control tree grows and shrinksThe control tree grows and shrinksdynamically in response to additionsdynamically in response to additionsand deletions to and from the multicastand deletions to and from the multicastgroupgroup..

TMTPTMTP–– Join Tree Join Tree

•• A new DM executes anA new DM executes anexpanding ringexpanding ring search searchto join the control tree.to join the control tree.

•• The The JoinTreeJoinTree algorithm algorithmUtilizes a time-to-liveUtilizes a time-to-livevalue (TTL).value (TTL).

While (While (NotDoneNotDone){){ Multicast a SEARCH-PARENT Multicast a SEARCH-PARENT msgmsg Collect Collect respondsesrespondses If (no responses)If (no responses) Increment TTL // try again Increment TTL // try again Else Else select closet respondent as parent select closet respondent as parent send JOIN-REQ to parent send JOIN-REQ to parent wait for JOIN-CONFIRM reply wait for JOIN-CONFIRM reply if (JOIN-CONFIRM received) if (JOIN-CONFIRM received) NotDoneNotDone = False = False Else //try again Else //try again}}

TMTP TMTP –– Leave Tree Leave Tree

•• A DM only leave theA DM only leave thetree after its last localtree after its last localmember leaves themember leaves thegroup.group.

•• Internal managers isInternal managers iscomplicated.complicated.

•• Leaf managers isLeaf managers isstraightforward.straightforward.

If ( I am a leaf manager)If ( I am a leaf manager) send LEAVE-TREE to parent send LEAVE-TREE to parent receive LEAVE-CONFIRM receive LEAVE-CONFIRM terminate terminateElse // I am an internal managerElse // I am an internal manager FullfillFullfill all pending obligations all pending obligations send FIND-NEW-PARENT to send FIND-NEW-PARENT to

childrenchildren receive FIND-NEW-PARENT receive FIND-NEW-PARENT

from all childrenfrom all children send LEAVE-TREE to parent send LEAVE-TREE to parent

TMTP TMTP –– error control(1) error control(1)

An important concept:An important concept: - - limited scope multicast messageslimited scope multicast messages

–– It restricts the scope of a multicastIt restricts the scope of a multicastmessage.message.

–– It sets the TTL value in IP header:It sets the TTL value in IP header:multicast radius.multicast radius.

TMTP TMTP –– error control(2) error control(2)

TMTP uses 2 error control techniques:TMTP uses 2 error control techniques:–– sender initiated approach: sender initiated approach:

•• Periodic positive ACK for receiver,Periodic positive ACK for receiver,•• Timeout,Timeout,•• Retransmissions (limited scope multicast).Retransmissions (limited scope multicast).

–– receiver initiated approach: receiver initiated approach:•• Negative ACK (NACK) to sender,Negative ACK (NACK) to sender,•• NACkNACk is restricted and suppressed, is restricted and suppressed,•• Retransmissions (limited scope multicast).Retransmissions (limited scope multicast).

TMTP TMTP ––Flow controlFlow control

•• Window-based flowWindow-based flowcontrolcontrol

•• 2 timers:2 timers: TTretrans retrans and Tand Tackack

•• TTretransretrans =n*T=n*Tack ack , n=3, n=3

Timer TimerTTackack T Tackack T Tackack

TTretransretrans

T Tretransretrans ++ TTackack

TTretrans retrans +2 T+2 Tackack

Test environment (2)Test environment (2)

•• We use standard IP multicast;We use standard IP multicast;•• We implement a sender-initiated reliableWe implement a sender-initiated reliable

multicast transport agent using ns2;multicast transport agent using ns2;•• TTackack = RTT, = RTT, TTretransretrans=3*T=3*Tackack

•• multicast trafficmulticast traffic

Performance measurePerformance measure

•• End-to-end delayEnd-to-end delay•• Packet lossPacket loss•• Bandwidth consumingBandwidth consuming

Some commentsSome comments

•• It is not It is not flexibleflexible

•• periodically periodically JoinTreeJoinTree to change hierarchyto change hierarchy

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•• ReferenceReference [1] M. [1] M. BanikazemiBanikazemi. . ““IP Multicasting: Concepts, Algorithms, andIP Multicasting: Concepts, Algorithms, and

Protocols, IGMP, RPM, CBT, DVMRP, MOSPF, PIM, MBONE,Protocols, IGMP, RPM, CBT, DVMRP, MOSPF, PIM, MBONE,””;;http://http://charlycharly..kjistkjist.ac..ac.krkr/~/~dwleedwlee/homepage//homepage/ipmulitcastipmulitcast..htmhtm

••   •• [2] B. Williamson. [2] B. Williamson. ““Developing IP Multicasting Networks Volume 1 -Developing IP Multicasting Networks Volume 1 -

Distance Vector Multicast Routing Protocol and Multicast OpenDistance Vector Multicast Routing Protocol and Multicast OpenShortest Path First,Shortest Path First,”” pp. 106-127 pp.194-211, Cisco Press, 2000. pp. 106-127 pp.194-211, Cisco Press, 2000.

••   •• [3] E. C. Douglas, [3] E. C. Douglas, ““Internetworking with TCP/IP Volume 1 - InternetInternetworking with TCP/IP Volume 1 - Internet

Multicasting (IGMP),Multicasting (IGMP),”” pp. 289-302, Prentice-Hall, Inc., 1995. pp. 289-302, Prentice-Hall, Inc., 1995.••   •• [4] S. [4] S. DeeringDeering, D. , D. EstrinEstrin, D. , D. FarinacciFarinacci, V. Jacobson, C. G. Liu, and L., V. Jacobson, C. G. Liu, and L.

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http://www.research.http://www.research.attatt.com/~.com/~breslaubreslau//vintvint/trace.html/trace.html••   •• [13] C. [13] C. HanleHanle and M. and M. HofmannHofmann, , ““Performance Comparison ofPerformance Comparison of

Reliable Multicast Protocols using the Network Simulator ns-Reliable Multicast Protocols using the Network Simulator ns-2,2,”” Proceedings of IEEE Conference on Local ComputerProceedings of IEEE Conference on Local ComputerNetworks (LCN)Networks (LCN), Boston, MA, USA, October 11-14, 1998., Boston, MA, USA, October 11-14, 1998.

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Networks Networks –– Simulation scenarios, Simulation scenarios,”” M. M. SciSci. Thesis,. Thesis,Department of Engineering Science, Simon Fraser University,Department of Engineering Science, Simon Fraser University,Oct. 2000, pp. 24-30.Oct. 2000, pp. 24-30.

••   •• [15] R. [15] R. YavatkarYavatkar, J. , J. GriffioenGriffioen, and M. , and M. SudaSuda. . ““A ReliableA Reliable

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Individual contributionIndividual contribution

•• Chao Chao Li: topology constructionLi: topology construction centralized approach centralized approach•• Thomas Su: topology constructionThomas Su: topology construction SRM SRM background traffic background traffic•• Cheng Lu: building a TMTP agent intoCheng Lu: building a TMTP agent into

ns2ns2

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Thanks Thanks