RMCP (Relayed Multi-Cast Protocol)

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RMCP (Relayed Multi-Cast Protocol)

• Presented by Juyoung Park
• 13th October 2005

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IF I

• If I could have watch 2002 Worldcup soccer games
  in my office through computer?
• If I can watch a most popular TV drama while Im
  in office without TV set?
• DONT IMAGINE ONLY!USE INTERNET BROADCASTING
  SERVICE !!

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Contents

• Background
• Introduction to RMCP SERIES
• CONCLUSION
• Reference
• QA

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Were on

• Background
• The Best way of Internet Broadcasting service
• Pros and Cons of IP multicast
• ALTERNATIVE WAYS of IP multicast
• Introduction to RMCP SERIES
• CONCLUSION
• Reference
• QA

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BACKGROUND

• Considerable TWO MAIN CATEGORIES of Internet
  broadcasting services are
• Internet On-demand Broadcasting
• Internet VoD System
• Jukebox
• Internet Live Broadcasting
• Internet Live TV (IP TV)
• Live Radio Broadcasting
• Stock Tickers and so on..

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BACKGROUND

• What is the BEST WAY of supporting Internet Live
  Broadcasting service?
• The answer would be IP MULTICAST !!
• Why?
• It CAN HANDLE hundreds of thousands of
  SIMULTANEOUS users.
• Because it can
• SAVE network RESOURCES EFFICIENTLY
• REDUCE the load of a sending nodes DRAMATICALLY

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BACKGROUND

• But, IP MULTICAST needs
• Enough MONEY
• TECHNICAL Solutions
• Complexity
• Functional limitations
• Limited data delivery service
• DEPLOYMENT
• Timing

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BACKGROUND

• So, WE CANNOT USE IP MULTICAST RIGHT NOW!

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BACKGROUND

• Then, is there other way of serving hundreds of
  thousands of simultaneous connection requests
  EFFICIENTLY on the Internet?
• YES, many efforts to EMULATE IP MULTICAST!As an
  ALTERNATIVE WAY OF IP MULTICAST
• Replicated IP Unicast
• Overlay Multicast

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ALTERNATIVE WAYS OF IP MULTICAST (1/2)

• Replicated Unicast mechanism
• How to?
• A server unicasts to each receivers ITERATIVELY.
• Weak Points
• Wasting network resources too much.
• Increasing the load of sender drastically.
• Good Points
• The EASIST WAY of implementing or deploying
  service.

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ALTERNATIVE WAYS OF IP MULTICAST (2/2)

• Overlay Multicast mechanism
• How to?
• EACH END HOSTS or SPECIAL DEVICES emulates the IP
  forwarding mechanism like multicast router.
• Weak Points
• End host may face to system or power failures.
• So, specially designed mechanism is highly needed
  to keep overlay multicast robust.
• Good Points
• EASIER WAY of implementing or deploying service.
• Efficient Usage of Network resources.

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THE AIM of RMCP

• It has intention to accelerate Internet
  broadcasting services on the current Internet.

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Were on

• Background
• Introduction to RMCP SERIES
• RMCP motivation
• RMCP-1 Framework
• RMCP-2 one-to-many distribution
• Control scheme of RMCP-2
• Data delivery scheme of RMCP-2
• RMCP-2 testing efforts
• RMCP-3 many-to-many interactive
• CONCLUSION
• Reference
• QA

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RMCP Motivation (1/3)

• Research Motivation
• Multicast CAN provides an efficient delivering
  mechanism for 1N or NN communications
• But, it has not been deployed for the current
  internet
• So, We need a solution to prompt IP multicast
  deployment
• Also, End-host and its applications are ready to
  use IP Multicast

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RMCP Motivation (2/3)

• Several mechanisms have been proposed.
• Some mechanisms need special network devices
• Some mechanisms depend on specific applications
• No standardization is set

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RMCP Motivation (3/3)

• So,
• We want to make an efficient overlay multicast
  mechanism.
• Which can prompt IP multicast service right now
  without changing the Infrastructure of backbone
  network
• Which follows international standard

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RMCP

• Goal
• To construct and manage an optimal relayed
  multicast data delivery path.

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RMCP

• Components

RMCP Data Delivery Path (when longest path is
constructed)
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RMCP

• What is RMCP?
• RMCP is one of overlay/application-layer/relayed
  multicast protocol.
• RMCP is the first one which follows international
  standardization process.
• RMCP consists of 3 separated specification.

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RMCP

• 3 separated specification?
• RMCP-1 A framework
• RMCP-2 Specification for SIMPLEX group
  applications
• RMCP-3 Specification for N-PLEX group
  applications

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RMCP

• Current State
• RMCP-1
• ITU-T Recommendation ISO IS Finished (0204)
• RMCP-2
• ITU-T draft text ISO CD processing (03)
• Expecting ITU-T LC procedure in 2006.
• RMCP-3
• ITU-T draft text ISO WD processing (04)

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RMCP-1 IN DETAIL

• A framework for Relayed Multi-Cast Protocol
• It categorizes present Internet group services
  into FOUR.
• 1N real-time data delivery
• 1N reliable data delivery
• NN real-time data delivery
• NN reliable data delivery

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RMCP-1 IN DETAIL

• A framework for Relayed Multi-Cast Protocol
• It defines two possible relayed delivery path
  construction and guides two additional
  protocols.
• 1N Overlay Multicast Data Delivery (RMCP-2)
• NN Overlay Multicast Data Delivery (RMCP-3)
• It shows a feasible Internet broadcasting service
  scenario by using RMCP.

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RMCP-1 IN DETAIL
One-to-many group applications?
Data Sender SMA
Session Manager
Reliable real-time uni-directional multicast
MA
Data Receiver RMA
MA
Data Receiver RMA
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RMCP-1 IN DETAIL
Many-to-many group applications?
Data Sender/Receiver SMA
Session Manager
Reliable real-time bi-directional multicast
MA
Data Sender/Receiver SMA
MA
Data Sender/Receiver SMA
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RMCP-1 IN DETAIL

• Relationship among RMCP-series

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RMCP-2 IN BRIEF

• What is RMCP-2
• A real protocol which can manage one-to-many
  overlay multicast network (so called overlay
  multicast tree)

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RMCP-2 IN BRIEF

• Some noticeable RMCP-2 features are
• 1) Initialization/ Termination
• Bootstrapping
• 2) Map discovery
• Inside local broadcast/multicast area
• Outside the area
• 3) Late Join / Early Leave
• Construct tree automatically
• 4) Maintenance
• Status monitoring
• Network fault recovery (loop, partition)
• Tree improvement
• 5) Data delivery scheme
• According to data profile

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Control Scheme in RMCP-2 (1/3)

• Exchanging Control Messages
• Media Server ? SM (unicast) implicitly
• Generic Session Information Session ID, the
  preferred data channel type, etc
• (S)MA ? SM (unicast) explicitly
• (S)MA ? MA (unicast) explicitly

session manager
media server
media player
Multicast Area
Multicast Area
Unicast Area
MA (Multicast Agent)
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Control Scheme in RMCP-2 (2/3)

• Control Messages of RMCP (Contd)

Operations Messages Meaning From To
Session Initialization SUBSREQ Subscription request MA SM
Session Initialization SUBSANS Subscription answer SM MA
Tree initialization RELREQ Relay request CMA PMA
Tree initialization RELANS Relay answer PMA CMA
Session leave LEAVREQ Leave request SM/PMA/CMA MA/CMA/PMA
Session leave LEAVANS Leave answer MA/CMA/PMA SM/PMA/CMA
Session Termination TERMREQ Termination request SM/PMA SMA/CMA
Session Termination TERMANS Termination answer SMA/CMA SM/PMA
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Control Scheme in RMCP-2 (3/3)

• Message Types

Operations Messages Meaning From To
Session Maintenance HB Heart beat SMA/PMA MA/CMA
Session Monitoring STREQ Status report request SM MA
Session Monitoring STANS Status report MA SM
Session Monitoring STCOLREQ Status collect request PMA CMA
Session Monitoring STCOLANS Status collect answer CMA PMA
MAP discovery PPROBREQ Parent probe request MA MA
MAP discovery PPROBANS Parent probe answer MA MA
HMA selection HSOLICIT Head solicit MA Local Net.
HMA selection HANNOUNCE Head announce HMA Local Net.
HMA selection HLEAVE Head leave HMA Local Net.
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RMCP-2 data delivery (1/2)

• Delivering Data
• Media Server (Sender) ? SMA (Multicast Agents)
  Multicast
• (S)MA ? MA Unicast
• MA ? Media Player (Receiver) Multicast

media server
media player
Multicast Area
Multicast Area
unicast tunneling
Unicast Area
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RMCP-2 data delivery (1/2)

• But RMCP-2 can use any kind of data delivery
  scheme.
• For real-time data delivery
• IP-in-IP, CIPE, UDP tunneling for Real-time data
  delivery ? described in Annex B
• For reliable data delivery
• TCP tunneling for Reliable data delivery?
  described in Annex C

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RMCP-2 IN DETAIL

• Bootstrapping
• A new joiner dont know any participated node of
  the session.
• After successful subscription, SM gives MA list
  to the new joiner (MA) as bootstrapping
  information.
• But, each new joiner should explore its network
  by itself because SM cannot know the network
  topology exactly.

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RMCP-2 IN DETAIL

• Neighbor Discovery (1/2)
• Inside of local multicast area
• Sometimes and always, a node in the same network
  would be the first candidate for its parent.

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RMCP-2 IN DETAIL

• Neighbor Discovery (2/2)
• Outside of local broadcast network
• explore and then measure
• MA does not have any information on physical
  network

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RMCP-2 IN DETAIL

• Tree construction
• Each MAs asks data relay to closest neighbor with
  hop-by-hop manner.

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RMCP-2 IN DETAIL

• Tree monitoring/maintenance
• A session manager can monitor participants
  arbitrarily.
• Each MA can detect and recover network fault by
  itself.

SM
STREQ
STREQ
STANS
STANS
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RMCP-2 IN DETAIL

• Tree improvement
• Overlay multicast mechanism cannot guarantee
  whether the constructed tree is optimized.
• RMCP-2 probes neighbors continuously and switch
  its parents at need.

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RMCP-2 Implementation (1/3)

• Implemented system
• Implemented System Environment RedHat 8.0 , C,
  Gtk
• Implemented components SM MA (2002.06)
• Data transmission channel IP-IP Tunneling, TCP,
  UDP

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RMCP-2 Implementation (2/3)

• Demonstration (past)
• Internet Real-time broadcasting on the APAN
  (2003.04)
• Internet Real-time broadcasting at the ITU-T SG17
  meeting (2003.09)
• On going Regular Test of Internet Real-time
  streaming video service among ETRI, CNU, and
  Kyushu Univ.

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RMCP-2 Implementation (3/3)
MA Interface
sm Interface
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RMCP-2 Testbed
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RMCP-2 Test
When RMCP is applied to IPTV alike service?
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RMCP-3 IN BRIEF

• RMCP-3 is under construction.
• It includes NN tree construction mechanism.

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Were on

• Background
• Introduction to RMCP SERIES
• CONCLUSION
• Reference
• QA

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CONCLUSION

• Now, WHAT CAN WE DO with RMCP? (1/2)
• EARLY STAGE
• RMCP as an International Standard CAN CATALYZE
  Internet group service!
• MID STAGE
• RMCP CAN act as an INTERIM SOLUTION for group
  service during the IP Multicast is being deployed.

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CONCLUSION

• Now, WHAT CAN WE DO with RMCP? (2/2)
• LAST STAGE
• RMCP CAN SURVIVE after the IP Multicast is Fully
  deployed in the next generation network.
• Personal internet live broadcasting services.
• As a solution for Inter-Domain multicast issues.
• For mobile multicast!

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Were on

• Background
• Introduction to RMCP SERIES
• CONCLUSION
• Reference
• QA

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References

• RMCP Official Home-page, http//ectp.etri.re.kr/

• RMCP DOCUMENTS
• RMCP-1 Framework,ITU-T X.603 ISO/IEC 16512-1
• RMCP-2 for Simplex Group Applications, 2nd CD
  ballot text of ITU-T X.603.1 ISO/IEC 16512-2
• RMCP-3 for N-plex Group Applications, 2nd WD
  ballot text of ITU-T X.603.2 ISO/IEC 16512-3

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Thank you!

• Juyoung Park
• Senior Researcher/Ph.D
• Protocol Engineering Center, ETRI
• jypark_at_etri.re.kr
• http//ectp.etri.re.kr/jypark