Ims content distributionnetworks

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Ims content distributionnetworks

  1. 1. P2P Content Distribution forMultimedia Services inIMS-based Telco Environments<br />Alex Bikfalvi, Jaime Garcia, Ivan Vidal, Francisco Valera<br />
  2. 2. Overview: P2P and IMS?<br />Peer-to-peer Technologies<br />… what is P2P (very brief)?<br />… why P2P?<br />… what content?<br />… how?<br />Next Generation Networks<br />… IMS & NGN?<br />… what is NGN/IMS?<br />… why IMS?<br />… how?<br />February 3, 2009<br />2<br />Multimedia Services<br />Does make sense combining P2P and NGN (IMS) technologies?<br />How can we do this?<br />What services can benefit from P2P content distribution?<br />What are the advantages for the telcos? But for the users?<br />
  3. 3. Outline<br />(I) Multimedia services in today’s Internet<br />(II) IMS – a multimedia service platform<br />(III) P2P for multimedia content<br />(IV) A content distribution service for IMS<br />February 3, 2009<br />3<br />
  4. 4. Part I: Multimedia Services<br />Multimedia services in today’s Internet<br />February 3, 2009<br />4<br />
  5. 5. The Internet... in 2004<br />P2P traffic was 60% and rising<br />ISPs identified P2P as a major challenge in network design<br />It affects the QoS for all users<br />Mostly, file-sharing: BitTorrent, eDonkey, Kad, Gnutella<br />February 3, 2009<br />5<br />Source: Cache Logic “P2P in 2005”<br />
  6. 6. The Internet… in 2007<br />Lately… the HTTP traffic is gaining the share back<br />… in terms of percentage of total traffic (not absolute value)<br />February 3, 2009<br />6<br />Source: Magid Media Futures survey<br />
  7. 7. The Internet… in 2007 and beyond<br />More than a third of the HTTP traffic is video streaming<br />YouTube is the most popular; counts for around 20%<br />That’s about 10% of all Internet traffic<br />February 3, 2009<br />7<br />Source: Magid Media Futures survey<br />The (near)future…<br />Internet video, the new broadband “killer”application?<br />More“***Tube” service providers?<br />User generated content and commercial content<br />
  8. 8. Video content distribution<br />Growing user demand<br />Increases bandwidth costs for the service providers<br />YouTube: ≈ 25 PB / month ≈ 1.2 M$ / month<br />Increases bandwidth demands for the ISPs<br />Consequences<br />(Popular) Service providers expect an increase in costs at the same quality of service<br />Deploying/contracting CDN capacity<br />ISPs need to provision new capacity to meet the demand<br />Only selling capacity is not a good business plan for telcos<br />February 3, 2009<br />8<br />Service Provider<br />Content Distribution Network<br />Internet Service/Access Provider<br />(Telco)<br />Internet Service/Access Provider<br />(Telco)<br />Internet Service/Access Provider<br />(Telco)<br />
  9. 9. Part II: IMS & NGN<br />IMS as a multimedia service platform for Next Generation Networks<br />February 3, 2009<br />9<br />
  10. 10. The next generation…<br />… service oriented architectures<br />Telco keywords<br />Triple-play packages: voice & TV & Internet<br />Telcos don’t make most $$$ by selling bandwidth<br />Telcos -> intermediary entities for service providers<br />Convergence: legacy networks -> next generation (IP)<br />February 3, 2009<br />10<br />Telco<br />(Internet Access Provider)<br />End-User<br />Service Provider<br />IP Core Network<br />Common Management & Service & Control Functions<br />xDSL<br />PSTN<br />Cable<br />Cable<br />GSM/3G<br />PSTN<br />xDSL<br />GSM/3G<br />
  11. 11. IP Multimedia Subsystem<br />A platform for IP multimedia services<br />Initially designed by 3GPP as an evolution of GSM/UMTS<br />Currently extended to many more access networks<br />Core of a Next Generation Network (TISPAN)<br />February 3, 2009<br />11<br />Service Providers<br />IP Multimedia Core Network Subsystem<br />Service Layer<br />Transport Control Functions<br />Transport Layer<br />IMS Gateways<br />Legacy terminals<br />Other Networks<br />Core Network<br />Access Networks<br />3GPPterminals<br />IMS terminals<br />Telco<br />
  12. 12. IMS: the basics<br />Functional entities connected by standardized interfaces<br />Main purpose: creation of sessions to multimedia sessions<br />Most of them handle the signaling not the media<br />February 3, 2009<br />12<br />Conferencing AS<br />Application<br />Servers<br />IPTV AS<br />Voice AS<br />Service Layer <br />(Applications)<br />VoD AS<br />P-CSCF<br />Call Session Control Functions<br />P-CSCF<br />S-CSCF<br />HSS<br />P-CSCF<br />Service Layer (IMS)<br />I-CSCF<br />UE<br />UE<br />Access Networks<br />Access Networks<br />UE<br />UE<br />User Equipments<br />Core Network<br />UE<br />Access Networks<br />UE<br />Access Networks<br />Transport Layer<br />UE<br />UE<br />UE<br />UE<br />
  13. 13. IMS: session signaling<br />IMS uses SIP for session signaling<br />Like a handshake between parties, before multimedia data can be exchanged<br />Independent on transport layer (uses URIs to identify resources)<br />SIP network elements<br />User agents<br />Servers: proxies, registrars, redirect servers<br />In IMS the Call Session Control Functions are SIP servers<br />Proxy-CSCF: the local proxy server for an User Equipment<br />Interrogating-CSCF: the role of the registrar<br />Serving-CSCF: proxy server performing session control<br />February 3, 2009<br />13<br />
  14. 14. IMS: session signaling example<br />A SIP example:<br />February 3, 2009<br />14<br />alice@atlanta.com @ 10.0.0.45<br />bob@biloxi.com @ 130.4.1.45<br />alice@atlanta.com<br />10.0.0.45<br />bob@biloxi.com<br />130.4.1.45<br />atlanta.com<br />10.0.0.1<br />biloxi.com<br />130.4.1.1<br />DNS<br />DNS Query: SRV _sip.biloxi.com<br />DNS Response: 130.4.1.1<br />INVITE sip:bob@biloxi.com<br />INVITE sip:bob@biloxi.com<br />Request Message<br />Status Message<br />200 OK<br />200 OK<br />ACK sip:bob@biloxi.com<br />ACK sip:bob@biloxi.com<br />
  15. 15. IMS: session signaling example<br />Session description protocol (SDP)<br />February 3, 2009<br />15<br />alice@atlanta.com<br />bob@biloxi.com<br />Session Negotiation<br />INVITE sip:bob@biloxi.com<br />SDP: IP, port, codec<br />INVITE sip:bob@biloxi.com<br />SDP: IP, port, codec<br />183 Session Progress<br />SDP: IP, port, codec<br />183 Session Progress<br />SDP: IP, port, codec<br />200 OK<br />200 OK<br />ACK sip:bob@biloxi.com<br />ACK sip:bob@biloxi.com<br />
  16. 16. IMS: session signaling example<br />In IMS each users has a dedicated SIP server:<br />In the access (visited) network: the P-CSCF<br />In the home network: the S-CSCF<br />Each network has a I-CSCF (the role of the registrar)<br />February 3, 2009<br />16<br />visited1.com<br />atlanta.com<br />biloxi.com<br />visited2.com<br />alice@atlanta.com<br />pcscf.visited1.com<br />scscf.atlanta.com<br /> biloxi.com<br /> scscf.biloxi.com<br />pcscf.visited2.com<br />bob@biloxi<br />UE<br />P-CSCF<br />S-CSCF<br />I-CSCF<br />S-CSCF<br />P-CSCF<br />UE<br />INVITE<br />INVITE<br />INVITE<br />INVITE<br />INVITE<br />INVITE<br />200 OK<br />200 OK<br />200 OK<br />200 OK<br />200 OK<br />200 OK<br />
  17. 17. IMS applications<br />The S-CSCF perform service control based on user’s service profile<br />Used to implement application servers<br />Example: IPTV application server<br />February 3, 2009<br />17<br />srv.atlanta.com:5999<br />RTSP/UDP<br />alice@atlanta.com<br />pcscf.atlanta.com<br />scscf.atlanta.com<br />iptv.atlanta.com<br />UE<br />P-CSCF<br />S-CSCF<br />AS<br />INVITE iptv@atlanta.com<br />INVITE iptv@atlanta.com<br />INVITE iptv@atlanta.com<br />Service Control<br />183 Session Progress<br />SDP: srv.atlanta.com:5999<br />RTSP/UDP<br />183 Session Progress<br />SDP: srv.atlanta.com:5999<br />RTSP/UDP<br />183 Session Progress<br />SDP: srv.atlanta.com:5999<br />RTSP/UDP<br />
  18. 18. Part III: P2P Multimedia Content Distribution<br />P2P technologies for multimedia content<br />The architecture of an IMS content distribution service<br />February 3, 2009<br />18<br />
  19. 19. Content distribution technologies<br />What are IMS/NGN advantages?<br />Multiple transport technologies<br />Use of broadband and quality-of-service<br />Separated service and transport functions<br />Generalized mobility<br />However… media (especially video) streaming is extremely expensive<br />Applications target a lot of receivers<br />We need support at the transport layer<br />What are the options?<br />IP multicast<br />Content distribution network<br />Peer-to-peer<br />February 3, 2009<br />19<br />Media Server<br />IMS<br />IMS Terminals (set-top boxes)<br />
  20. 20. Case study: video streaming<br />What are IMS/NGN advantages?<br />Multiple transport technologies<br />Use of broadband and quality-of-service<br />Separated service and transport functions<br />Generalized mobility<br />However… media (especially video) streaming is extremely expensive<br />Applications target a lot of receivers<br />We need support at the transport layer<br />What are the options?<br />IP multicast<br />Content distribution network<br />Peer-to-peer<br />February 3, 2009<br />20<br />Media Server<br />IMS<br />IMS Terminals (set-top boxes)<br />
  21. 21. Case study: video streaming<br />What are IMS/NGN advantages?<br />Multiple transport technologies<br />Use of broadband and quality-of-service<br />Separated service and transport functions<br />Generalized mobility<br />However… media (especially video) streaming is extremely expensive<br />Applications target a lot of receivers<br />We need support at the transport layer<br />What are the options?<br />IP multicast<br />Content distribution network<br />Peer-to-peer<br />February 3, 2009<br />21<br />Media Server<br />IMS<br />IMS Terminals (set-top boxes)<br />
  22. 22. Case study: video streaming<br />What are IMS/NGN advantages?<br />Multiple transport technologies<br />Use of broadband and quality-of-service<br />Separated service and transport functions<br />Generalized mobility<br />However… media (especially video) streaming is extremely expensive<br />Applications target a lot of receivers<br />We need support at the transport layer<br />What are the options?<br />IP multicast<br />Content distribution network<br />Peer-to-peer<br />February 3, 2009<br />22<br />Media Server<br />IMS<br />IMS Terminals (set-top boxes)<br />
  23. 23. P2P issues<br />P2P looks fine… but:<br />Peers may have an unpredictable behavior<br />Resources (bandwidth, delay) may not be adequate<br />We need uplink resources as well<br />February 3, 2009<br />23<br />However,in NGN/IMS:<br />Some peers may be considered stable (e.g. set-top boxes)<br />Resources are known and reserved<br />Once reserved, they are guaranteed<br />Fan-out: 3<br />Fan-out: 2<br />Fan-out: 2<br />
  24. 24. Trees vs. meshes<br />Trees<br />Mimic multicast<br />Each peer selects a parent peer<br />The content/stream can be divided and sent across several trees<br />Meshes<br />A peer obtains pieces from any available peer<br />There is not a strict relationship: child-parent<br />Instead peers can collaborate in sharing pieces<br />February 3, 2009<br />24<br />
  25. 25. Where P2P?<br />P2P media vs. P2P signaling<br />Until now we discussed P2P in media plane <br />What is P2P signaling?<br />Discovery of other peers using a P2P protocol<br />For trees: a structured protocol (DHT) to find a parent<br />For meshes: an unstructured protocol to find other peers<br />With P2P signaling<br />The functionality is distributed<br />No need of a central entity<br />February 3, 2009<br />25<br />
  26. 26. Part IV: A P2P Content Distribution Service for IMS<br />(work in progress)<br />February 3, 2009<br />26<br />
  27. 27. Incentives for P2P<br />IMS network capabilities<br />Smart IMS devices as peers: residential gateways, set-top boxes<br />Transport: quality of service, resource reservation<br />Telco policies: using capacity that is physically available but not paid for by the user<br />Advantages<br />All advantages of IMS: AAA, mobility, QoS<br />Performance improvement goals<br />Reduce load on core network / service provider<br />Keep most of the traffic in the access network<br />The telco controls the network<br />P2P in a managed environment -> optimizations<br />Business model<br />Service providers -> Telco -> Users<br />February 3, 2009<br />27<br />
  28. 28. Why such a service?<br />Video content may be the new killer app, but…<br />… other services can benefit from P2P too (conferencing, software distribution)<br />… even video may have different requirements (IPTV ≠ VoD)<br />Content Distribution Service Provider<br />Intermediary between the Multimedia Content Service Provider and IMS + transport layer<br />Makes the content distribution transparent for the MCS<br />Hides the specifics of the media content to the IMS/transport<br />February 3, 2009<br />28<br />The Content Distribution Service is intended as an adaptation layer between the multimedia content and the mechanism (P2P or otherwise) used for content distribution<br />
  29. 29. The idea<br />February 3, 2009<br />29<br />Multimedia Services<br />Content Distribution Service<br />AS<br />AS<br />AS<br />AS<br />IMS<br />Transport Network<br />UE<br />UE<br />UE<br />UE<br />UE<br />UE<br />
  30. 30. The idea: IPTV simple example<br />IPTV client<br />Needs the address, port of a host delivering the video<br />We call this host the content serving host<br />February 3, 2009<br />30<br />UE alice@atlanta.com<br />IPTV client<br />CDS client<br />cds.atlanta.com<br />INVITE cds@atlanta.com<br />SDP: provider=iptv3, ch=5<br />connect(ch5)<br />AS<br />INVITE cds@atlanta.com<br />SDP: provider=iptv3, ch=5<br />183 Session Progress<br />SDP: peer IP, port, protocol, codec<br />183 Session Progress<br />SDP: peer IP, port, protocol, codec<br />200 OK<br />200 OK<br />return IP, port, …<br />ACK cds@atlanta.com<br />ACK cds@atlanta.com<br />
  31. 31. The infrastructure<br />Different topologies for P2P<br />P2P between UEs (same/different access networks)<br />P2P between Edge Servers/Distribution servers<br />February 3, 2009<br />31<br />Content Distribution Service<br />IMS<br />AS<br />AS<br />AS<br />AS<br />Multimedia Services<br />Edge/Distribution Servers<br />P2P<br />P2P<br />P2P<br />P2P<br />User Equipment (IMS terminals)<br />
  32. 32. Business model<br />February 3, 2009<br />32<br />Third Party Service Providers<br />Trust Relationship<br />Pays for the services retaining a %<br />IMS<br />CDS Provider<br />Service Packager<br />Transport Provider<br />P2P streaming enabled network<br />User-Network Interface<br />Pay for data transport and third-party services<br />Set-top<br />boxes<br />Users<br />Telco<br />
  33. 33. Case Study: IPTV<br />Content: TV channels<br />Number of pieces of content: relatively low (hundreds)<br />Requirements<br />Access time very important (channel switching)<br />Low delay of live content (limited caching)<br />Constant streaming (no interruptions)<br />Design criteria<br />P2P signaling not an option: latency too large<br />Fast discovery of the content serving host (centralized, AS-based)<br />The edge server may improve performance – maybe P2P signaling is an option here?<br />February 3, 2009<br />33<br />
  34. 34. Case Study: Video-on-Demand<br />Content: published clips / user generated content<br />Number of pieces of content: high (very high)<br />Requirements<br />Initial access time not critical<br />Distributed content: caching/storage part of design<br />Constant streaming after video started<br />Design criteria <br />P2P signaling could be essential (a lot of content to index)<br />Redundancy<br />P2P protocol can be optimized (no tit-for-tat)<br />February 3, 2009<br />34<br />
  35. 35. …other applications<br />Other endeavors … telcos might pursuit<br />Distributed computing<br />Distributed storage<br />Delay tolerant transfers<br />Content distribution with social networking<br />February 3, 2009<br />35<br />
  36. 36. Conclusions<br />February 3, 2009<br />36<br />
  37. 37. Conclusions<br />P2P content distribution in IMS = P2P in a managed network<br />Does it make sense?<br />Bulk of the Internet traffic: P2P and video<br />Telcos don’t make money from selling bandwidth<br />IMS/NG is the right platform for telcos<br />P2P in the transport layer could be a cost-effective approach<br />TISPAN began working in this direction (first draft Nov ‘08)<br />But<br />Although 3GPP is pushing IMS standardization…<br />… deployment in near future is uncertain<br />February 3, 2009<br />37<br />
  38. 38. February 3, 2009<br />38<br />
  39. 39. February 3, 2009<br />39<br />

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