Contribución al Desarrollo de Soluciones Para la Integración de Métodos de Establecimiento de Sesión en Redes 4G. to Designing Suitable

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1 TESIS DOCTORAL Departamento de Ingeniería Telemática Doctorado en Tecnologías de las Comunicaciones Contribución al Desarrollo de Soluciones Para la Integración de Métodos de Establecimiento de Sesión en Redes 4G (Contribution to Designing Suitable Session Setup Solutions in 4G Networks) Autor: D. Antonio Cuevas Casado Director: Dr. José Ignacio Moreno Novella 17 th July 2006

2 Outlook Design suitable session setup solutions in 4G networks 1. Introduction, Objectives 2. State of the Art 3. Integrating Sessions: Requirements 4. 4G Proposed Architecture and Session Setup Support 5. Signalling 6. Validation 7. Conclusions Tesis Doctoral 1

3 Introduction, Context Migration of the circuit switched networks towards an IP world is happening: Vinton Cerf: no sense to keep two separate networks Reasons for such an important change Increase revenue due to ease of building new services over the Internet and their acceptance by the users Reduce costs to operators: manage only one network Tesis Doctoral 2

4 Introduction, Context For us, 4G is an Internet like network with extra features, many, such as mobility, already present in cellular networks A 4G network is not a 3G All-IP network (3G network with an IP overlay) Lots of research efforts in 4G networks Tesis Doctoral 3

5 Introduction, challenges and open points In 4G, terminals are IP hosts. Risks for the operators to become bit pipes Migration can not be avoided, avoid its bad consequences for the operators Convergence in business models?? still not clear. Thus One topic to still handle in 4G networks is session setup. The problems come from the fact that a session is composed of subsessions (transport, application) handled by different business entities Tesis Doctoral 4

6 Introduction, objectives Design Session Setup solutions integrating application and network layer aspects and services in 4G networks Focus on orchestration between the different entities, systems, modules But keeping Internet paradigm: transport & service separation Position the network operator in the core of the business value chain Analyze and compare different proposals & scenarios Tesis Doctoral 5

7 Outlook State of the Art See what is profitable, research opportunities matching our objectives Integrating Sessions: Requirements Sessions are split, advantages and requirements to integrate them 4G Proposed Architecture and Session Setup Support Design needed aspects, session setup techniques in different scenarios Signaling Closes the solution, important for understanding simulations Validation Methods, rules to design 4G networks Conclusions Tesis Doctoral 6

8 Outlook Introduction State of the Art See what is profitable, research opportunities matching our objectives Session Setup Techniques IMS 4G Integrating Sessions: Requirements 4G Proposed Architecture and Session Setup Support Signaling Validation Conclusions Tesis Doctoral 7

9 IETF session setup solutions RSVP: offer + answer. To setup transport sessions. Few parameters, simple model In the IntServ framework In the application layer: SIP & SDP (+SDPng) very adequate, plus mechanisms (RFCs) to coordinate SIP and QoS setup Lacks cost sharing parameters Tesis Doctoral 8

10 IMS SIP/SDP UE UTRAN PDF SGSN IMS P-CSCF IPv6 GGSN GPRS/ UMTS Application Server or OSA Gateway SIP/SDP IP external networks ISC Interface HSS S-CSCF Home Subscriber Server IMS signalling IP Flows SIP proxy infrastructure (CSCFs) integrated with 3G networks elements (HSS, GGSN -via the PDF-) Tesis Doctoral 9

11 4G research efforts Research efforts such as mobility, QoS and AAA in IP(v6) based networks Many existing solutions, challenge to integrate them Tests show that 4G can support Multimedia applications (which are the main applications concerned with session setup) Some works about session setup, but covering partial issues Tesis Doctoral 10

12 State of the art vs. thesis innovation & objectives IMS already fulfils our idea Semi walled garden business model But there is room to fit our research objectives: Enhance and migrate IMS it to 4G networks with many access technologies Support non proxied applications ( ) From partial 4G solutions to a complete framework Cover and compare all levels, entities, systems, business models, scenarios Tesis Doctoral 11

13 Outlook Introduction State of the Art Integrating Sessions: Requirements Sessions are split, advantages and requirements to integrate them Sessions in the different entities Business models, Session Integration Users Profiles 4G Proposed Architecture and Session Setup Support Signaling Validation Conclusions Tesis Doctoral 12

14 The 4 entities They control different aspects of the subsessions standing for a service Conferees (e.g. caller & callee in phone calls) VASPs: Services providers (they are also conferees) Proxies Network provider Tesis Doctoral 13

15 Session setup parameters Terminal dependent Parameters: Screen size, processing power 3rd party resource dependent parameters (network): mean BW, peak BW, error rate Mix: Codecs to employ, Network dependent parameters may be priced and related to users profiles. Which user profile should be followed when setting up sessions?: The Best, Caller s one,? Proposal: include cost sharing in session setup negotiation Tesis Doctoral 14

16 Business models, features to achieve Single sign-on Unified & non duplicated billing Service bundles, packaging Need of aggregating sessions See whether the next-presented business models can fulfill these features Tesis Doctoral 15

17 Internet Business model Not possible to aggregate sessions and thus to offer advanced features However, we need to support it Trust relationship Trust relationship 3rd Party Service Providers Network operator 3rd Party Service Providers Trust relationship Trust relationship Trust relationship Tesis Doctoral 16

18 Telephony Business model Easy to aggregate sessions and offer advanced features Will be overcome in 4G networks Network operator + Service provider Trust relationship Tesis Doctoral 17

19 Semi-walled garden business model To aggregate sessions and offer advanced features we to design appropriate mechanisms in 4G networks (Thesis Topic) Trust relationship 3rd Party Service Providers Trust relationship Network operator Tesis Doctoral 18

20 Users Profiles The NVUP. More complex than flat rates? Deutsche Telekom President: create different QoS classes but Interface to the users simple (flat rates) A problem: Application profiles may differ with NVUP. Example: NVUP discount on AF traffic from 20:00 to 8:00. News Streaming: Discount from 21:00 to 7:00 One of the pieces needed to solve it: the SVUP. Proposal to integrate the profiles (NVUP & applications) Tesis Doctoral 19

21 Conclusions Benefits of Semi-walled garden model QoS-enabled data transport seen as another service Need to integrate services sessions Cost sharing User profiles, NVUP; and the SVUP as a way to integrate all the profiles Need also to support Internet model and non IMS applications, coexistence See how to achieve this in 4G networks Tesis Doctoral 20

22 Outlook Introduction State of the Art Integrating Sessions: Requirements 4G Proposed Architecture and Session Setup Support Design needed aspects, session setup techniques in different scenarios Signaling Validation Systems Conclusions Orchestration Tesis Doctoral 21

23 Systems Internet MMSP AAA CN QoSB MMSP AA AN QoSB Tesis Doctoral 22

24 Systems-QoS Internet MMSP AA CN QoSB MMSP AA AN QoSB Tesis Doctoral 23

25 QoS System modules Control network usage not only for QoS but also for SLAs issues e.g. police NVUP: B.E.<64 kbps QoSBrokers, Hierarchical Push fine QoS control to the edges QoSBroker: PDP (like IMS PDF) + network management extra QoS handling possibilities Proposal specialize QoSBroker in network management and not in user control But still QoS tailored to users and applications thanks to interactions with AAA and MMSP Implicit signaling and QoSB gets user related data from AAA Controls network consumption and informs AAA Tesis Doctoral 24

26 Internet ER CR DiffServ CN No access control, No session No need of flow-user association QoS Broker Measurement system Measurement system MMSP VASP AAA system QoS Broker CR IntServ like AN, Access control, Sessions CR ER ER ER CR IntServ like AN QoS Broker AR AR AR AR Tesis Doctoral 25

27 Systems-MMSP Multi Media Service provisioning Platform (i.e. SIP proxies) Internet MMSP AAA CN QoSB MMSP AA AN QoSB Tesis Doctoral 26

28 MMSP modules Like in IMS, hierarchical split: AN-MMSP, CN-MMSP Match with the QoS split P-CSCF + S-CSCF in the AN-MMSP AN-MMSP does the QoS SETUP and needs to keep its state (no need in IMS since we have only QoS policy transfer) Extra QoS handling possibilities than in IMS All SIP routing via the CN-MMSP, alleviates this heavy task to the AN-MMSPs Tesis Doctoral 27

29 CN MMSP Internet MMSP CN MMSP AAA system (registrar service) AN MMSP AN AN MMSP AN MMSP QoS system AAA System VASP Users Tesis Doctoral 28

30 Systems-AAA Internet MMSP AAA CN QoSB MMSP AA AN QoSB Tesis Doctoral 29

31 AAA modules & decentralization proposal Aggregates the sessions other entities produce NAS: access session, user-packet mapping Decentralization: Not thesis main goal but it s an important aspect to handle Decentralize accounting and authorization: Delegation to AN-AA server: Diameter credit control credit server. Plus accounting consolidation Authorization by transfer of selected parts of the user profile (SAML). Concerns in roaming Authentication keeps being centralized in the CN_AAA home server Tesis Doctoral 30

32 Internet DiffServ CN AAA MMSP VASP IntServ like AN AA MMSP QoS System NAS Users Tesis Doctoral 31

33 Orchestration Authorization or distribution of users profiles? Privacy KO delivering parts of the user profile to not fully trusted AAA clients (service providers) Performance KO AAA Client and AAA system to understand services Proposal: deliver profiles to MMSP and QoSBroker. They are trusted and may represent a big % of the total subsessions & services Tesis Doctoral 32

34 Orchestration Several possibilities to authorize transport and services: MMSP AAA, MMSP QoSB MMSP obtains all the relevant user data from the AAA and then can ask for user and application tailored QoS VASP AAA, VASP QoSB, QoSB AAA the AAA does not need to deliver user profile to the VASPs who, still, can ask for QoS to the QoSB. QoSB will obtain the missing data from the AAA Tesis Doctoral 33

35 Orchestration AAA as sole network contact point: VASP AAA, Terminal QoSB, QoSB AAA Internet scenarios No entity informs the AAA about the application, QoS based on NVUP Terminal AAA (registration, done in every scenario) Terminal QoSB, QoSB AAA Thanks to the QoSB-AAA interaction we support more scenarios than in IMS Tesis Doctoral 34

36 Conclusion Holistic approach Solutions to give coherence to the session setup split presented before Many scenarios and possibilities evaluated (complete the evaluation with simulation) Coexistence of the several proposals and heterogeneous environments Scalability AN-CN QoS Setup in first SDP offer/answer exchange Tesis Doctoral 35

37 Outlook Introduction State of the Art Integrating Sessions: Requirements 4G Proposed Architecture and Session Setup Support Signaling Closes the solution Validation Conclusions Tesis Doctoral 36

38 Contributions summary Standard protocols enhanced to fit our needs and to co-operate between them Session identification and its exchange Aggregation of sessions Heterogeneous QoS and NAS sessions supported Registration Setup in MMSP, VASP, Internet scenarios SAML allows transferring user profile to AN-AA and thus delegating authorization to it. Tesis Doctoral 37

39 Outlook Introduction State of the Art Integrating Sessions: Requirements 4G Proposed Architecture and Session Setup Support Signaling Validation Methods to design 4G networks Simulation scenario Test results for the MN and MMSP strategies Conclusions Tesis Doctoral 38

40 Scenario The 4 CNs CN CN CN CN Tesis Doctoral 39

41 AN AN Scenario 1 of the 4 CNs AN AN QoSB AAA Internet AN MMSP AN AN AN Tesis Doctoral 40

42 Scenario 1 of the 32 ANs CN QoSB AA MMSP Tesis Doctoral 41

43 System load Nodes processing speed calculated to support 64 calls/s AN-MMSP calculations for the MN strategy 1 major Test Several measurements 2 minor tests Tesis Doctoral 42

44 Call setup time the system is overloaded!! Tiempos de inicio, fin y duración del establecimiento de las llamadas. 64 llamadas/s. Estrategia "MMSP" Llamadas (ordenadas por tiempo de inicio) Tiempo (s) Tesis Doctoral 43

45 However, no node is overloaded!! e.g. procesing time in the AN-AA Tiempo de procesamiento de los mensajes en un AN-AA 64 llamadas/s. Estrategia MMSP. Cada punto es un mensaje Tiempo de procesamiento del mensaje (s) Tiempo de de entrada del mensaje (s) Tesis Doctoral 44

46 but the AN-MMSP in the MMSP strategy Tiempo de procesamiento de los mensajes en un AN-MMSP. 64 llamadas/s. Estrategia MMSP. Cada punto es un mensaje 3 Tiempo de proceso del mensaje (s) Tiempo de entrada del mensaje (s) Tesis Doctoral 45

47 System Load No node overload but the system is overloaded (session setup time increases) Other tests Minimum load!= in setup time between the 2 strategies <=> the AN-MMSP speed maximum stable load this difference is bigger (45%) Effects of nodes on each other in a complex architecture Need for simulations, analytical results not enough even for this small experiment Tesis Doctoral 46

48 Peak of calls Call rate low rate, high rate, (during 1 s) low rate Measurements Session setup time Nodes processing speed Tesis Doctoral 47

49 Call Setup time. MMSP strategy Tiempo de establecimiento de las llamadas. Pico de llamadas. Estrategia MMSP 9 Tiempo de establecimiento (s) Tiempo de inicio de la llamada (s) Tesis Doctoral 48

50 Call Setup time. MN strategy lower peak and shorter time to recover Tiempo de establecimiento de las llamadas. Pico de llamadas. Estrategia MMSP 9 Tiempo de procesamiento (s) Tiempo de inicio de la llamada (s) Tesis Doctoral 49

51 The CN nodes present a peak... Tiempo de procesamiento de los mensajes en un CN-AAA. Pico de llamadas. Cada punto es un mensaje. Estrategia MN Tiempo de entrada del mensaje (s) Tesis Doctoral 50

52 and not the AN ones Tiempo de procesamiento de los mensajes en un AN-MMSP. Pico de llamadas. Cada punto es un mensaje. Estrategia MN 1.6 Tiempo de proceso del mensaje (s) Tiempo de entrada del mensaje (s) Tesis Doctoral 51

53 But for the AN-MMSP in the MMSP strategy Tiempo de procesamiento de los mensajes en un AN-MMSP. Pico de llamadas. Cada punto es un mensaje. Estrategia MMSP 1.6 Tiempo de proceso del mensaje (s) Tiempo de entrada del mensaje (s) Tesis Doctoral 52

54 Peak of calls AN-CN split advantage, peak present only in central nodes Influence of the AN-MMSP in recovering : in the MMSP strategy it presents a processing time peak and this strategy takes more time to recover Tesis Doctoral 53

55 Conclusion, methods to design 4G 1st holistic simulation Many nodes interacting, analytical approach not enough even in our small model Benefits of the hierarchical approach (peak of calls) Bottle necks: nodes with many interactions (AN-MMSP)=> reduce their load=> SIP routing at CN-MMSP Tesis Doctoral 54

56 Outlook State of the Art See what is profitable, research opportunities matching our objectives Integrating Sessions: Requirements Sessions are split, advantages and requirements to integrate them 4G Proposed Architecture and Session Setup Support Design needed aspects, session setup techniques in different scenarios Signaling Closes the solution, important for understanding simulations Validation Methods to design 4G networks Conclusions Tesis Doctoral 55

57 Conclusions IMS evolution and enhancement towards 4G First holistic 4G framework covering several scenarios, entities, systems Semiwalled model achieved but keeping Internet paradigm: transport and service separation Other scenarios supported Design decisions & approaches compared and analyzed Tesis Doctoral 56

58 Conclusion, avenues for research Multiparty calls, mobility=> extend our framework Anonimization, pseudonyms: single sign on vs. not tracking user activity Multicast MMSP+QoS interaction Tesis Doctoral 57

59 Conclusion, forecast for our proposal Consumers preferences determine all the aspects in the business (stop vs. non stop flights costs vs. price) Users need to find any advantage in the services Our framework is a service provisioning platform that may help create better services accepted by the users Or just compete in price but keeping user control Tesis Doctoral 58

60 TESIS DOCTORAL Departamento de Ingeniería Telemática Doctorado en Tecnologías de las Comunicaciones Contribución al Desarrollo de Soluciones Para la Integración de Métodos de Establecimiento de Sesión en Redes 4G (Contribution to Designing Suitable Session Setup Solutions in 4G Networks) Autor: D. Antonio Cuevas Casado Director: Dr. José Ignacio Moreno Novella