RMCP (Relayed Multi-Cast Protocol) Presented by Juyoung Park 13th October 2005
IF I … • If I could have watch 2002 Worldcup soccer games in my office through computer? • If I canwatch a most popular TV drama while I’m in office without TV set? • DON’T IMAGINE ONLY!USE INTERNET BROADCASTING SERVICE !!
Contents • Background • Introduction to RMCP SERIES • CONCLUSION • Reference • Q&A
We’re 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 • Q&A
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..
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 node’s DRAMATICALLY
But, IP MULTICAST needs; Enough MONEY TECHNICAL Solutions Complexity Functional limitations Limited data delivery service DEPLOYMENT Timing BACKGROUND
BACKGROUND • So, WE CANNOT USE IP MULTICAST RIGHT NOW!
BACKGROUND • Then, is there other way of serving hundreds of thousands of simultaneous connection requestsEFFICIENTLY on the Internet? • YES, many efforts to EMULATE IP MULTICAST!As an ”ALTERNATIVE WAY OF IP MULTICAST” • Replicated IP Unicast • Overlay Multicast
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.
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.
THE AIM of RMCP • It has intention to accelerate“Internet broadcasting services”on the current Internet.
We’re 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 • Q&A
RMCP Motivation (1/3) • Research Motivation • Multicast CAN provides an efficient delivering mechanism for 1:N or N:N 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
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
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
RMCP • Goal • To construct and manage an optimal relayed multicast data delivery path.
RMCP Session Manager Data Receiver+ RMA Data Sender + SMA Unicast Internet Data Receiver + RMA Data Receiver + RMA • Components RMCP Data Delivery Path (when longest path is constructed)
RMCP • What is RMCP? • RMCP is one of overlay/application-layer/relayed multicast protocol. • RMCP is the first one which followsinternational standardization process. • RMCP consists of 3 separated specification.
RMCP • 3 separated specification? • RMCP-1: A framework • RMCP-2: Specification for SIMPLEX group applications • RMCP-3: Specification for N-PLEX group applications
RMCP • Current State • RMCP-1 • ITU-T Recommendation & ISO IS Finished(’02~`04) • 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~)
RMCP-1 IN DETAIL • A framework for Relayed Multi-Cast Protocol • It categorizes present Internet group services into FOUR. • 1:N real-time data delivery • 1:N reliable data delivery • N:N real-time data delivery • N:N reliable data delivery
RMCP-1 IN DETAIL • A framework for Relayed Multi-Cast Protocol • It defines “two possible relayed delivery path construction” and guides two additional protocols. • 1:N Overlay Multicast Data Delivery (RMCP-2) • N:N Overlay Multicast Data Delivery (RMCP-3) • It shows a feasible Internet broadcasting service scenario by using RMCP.
RMCP-1 IN DETAIL Data Receiver+ RMA MA Data Receiver+ RMA RMCP-2 One-to-many group applications? Data Sender+ SMA Session Manager Reliable | real-time uni-directional multicast MA Data Receiver+ RMA MA Data Receiver+ RMA
RMCP-1 IN DETAIL Data Receiver+ RMA MA Data Receiver+ RMA RMCP-3 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
RMCP-1 IN DETAIL RMCP-1 : Framework RMCP-2 RMCP-3 • Relationship among RMCP-series
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)
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
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)
Control Scheme in RMCP-2 (2/3) • Control Messages of RMCP (Cont’d)
Control Scheme in RMCP-2 (3/3) • Message Types
RMCP-2 data delivery (1/2) MA : Multicast Agent • 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
RMCP-2 data delivery (1/2) MA (Multicast Agent) • 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
RMCP-2 IN DETAIL C F G • Bootstrapping • A new joiner don’t 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.
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.
RMCP-2 IN DETAIL G C B F C A A B G F A A B B C C D D D E E E F F G G E F D G A B C A B C • Neighbor Discovery (2/2) • Outside of local broadcast network; • explore and then measure • MA does not have any information on physical network
RMCP-2 IN DETAIL RELREQ RELANS • Tree construction • Each MAs asks data relay to closest neighbor with hop-by-hop manner.
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
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.
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
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.
RMCP-2 Implementation (3/3) MA Interface sm Interface
RMCP-2 Test When RMCP is applied to IPTV alike service?
RMCP-3 IN BRIEF • RMCP-3 is under construction. • It includes N:N tree construction mechanism.
We’re on • Background • Introduction to RMCP SERIES • CONCLUSION • Reference • Q&A
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.
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!
We’re on • Background • Introduction to RMCP SERIES • CONCLUSION • Reference • Q&A
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