1. Slide title In CAPITALS 50 pt Slide subtitle 32 pt Static Call Admission Control and Dimensioning of Media Gateways in IP based Mobile Core Networks Mika Isosaari Supervisor: prof Jorma Virtamo Instructor: Harri Lehtomäki, M.Sc.

2. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt © Ericsson AB 20052005-08-032 Contents  Introduction  General Structure of UMTS Release 5 Network  Media Gateway  Multiservice IP Transport Network  Network Dimensioning  Quality of Service  Mechanisms to Guarantee QoS  Static Admission Control  Simulations  Conclutions and Future Work

3. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt © Ericsson AB 20052005-08-033 Introduction  Background –VoIP vs. ToIP –How telecom grade speech can be transferred in connectionless IP network? –Multiservice IP network: speech only one of the services  Objectives –To study how circuit-switched speech can be transferred in an IP multiservice network so that a certain Quality of Service (QoS) level can be sustained –How static admission control methods work and what is their influence on network dimensioning

4. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt © Ericsson AB 20052005-08-034 Research methods  Literature study –ITU, 3GPP, IETF recommendation and specifications –Books and articles to get a more comprehensive picture of the subject  Numerical evaluation –Used in comparing different static admission control methods and their effect on dimensioning  Simulations –Show how the traffic intensity affects the utilization and resource demand

5. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt © Ericsson AB 20052005-08-035 General Structure of UMTS Release 5 Network  Three domains: Circuit-Switched (CS), Packet- Switched (PS) and IP Multimedia Subsystem (IMS) –This thesis focuses on CS domain

6. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt © Ericsson AB 20052005-08-036 Layered Architecture  Application layer  Network control layer  Connectivity layer –MGW –Backbone

7. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt © Ericsson AB 20052005-08-037 Media Gateway  PSTN/PLMN transport termination point  May support media conversion, bearer control and payload processing (e.g. transcoders and echo cancellers)  Nb User Plane traffic between MGWs is transported either over ATM or IP bearer  Logically resides at the border of the backbone, physically part of site configuration  Basic site infrastructure: Local Area Network (LAN) switches and site routers

8. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt © Ericsson AB 20052005-08-038 Multiservice IP Transport Network

9. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt © Ericsson AB 20052005-08-039 Telephony services in multiservice IP network  Strict requirements for Telephony over IP (ToIP) –when international telecommunication networks interwork with IP-based networks, the QoS experienced by the users should, as far as practicable, be the same as if there had been no interworking involved  Data Conversions and Protocols –MPLS, IP/UDP/RTP/NbUP, AMR/PCM…

10. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt © Ericsson AB 20052005-08-0310 Network Dimensioning  The whole planning process is influenced by the UMTS architecture and IP backbone when compared to traditional GSM network –overall architecture is very different –multiservice network –information is transferred in a form of packets in a connectionless network  Dimensioning Challenges –every traffic flow has an effect on all the other traffic flows and a wrongly configured service can lead to degradation of speech quality, which is not acceptable –when the speech is packet-based everything comes in practice a matter of probabilities

11. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt © Ericsson AB 20052005-08-0311 Quality of Service  Quality of Service (QoS) is the quality of a requested service as perceived by the customer and always meant end-to-end  Information Quality Parameters: delay, jitter, BER, PLR, data rate  QoS Architecture in UMTS Networks vs. QoS in Internet –Mapping of different quality classes important –E.g. with DiffServ: EF  conversational, AF  streaming / interactive, BE  background  Internet QoS: IntServ, DiffServ, MPLS(?), traffic engineering

12. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt © Ericsson AB 20052005-08-0312 Mechanisms to Guarantee Quality of Service  Network Level Mechanisms –Dimensioning –Overprovisioning –Architecture  Flow Level Mechanisms –Static Admission Control –Dynamic Admission Control  Packet Level Mechanisms

13. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt © Ericsson AB 20052005-08-0313 Static Admission Control  Basic idea: permanently allocated resources in the backbone network set by the service provider  MGW is in practice the most logical choice in the CN for the implementation (may work together with routers in the backbone)  Main advantage of static methods is their simplicity  Downside is the inefficient usage of network resources  Two most important models: pipe model and hose model

14. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt © Ericsson AB 20052005-08-0314 Static Admission Control  Pipe model –traditional model how provisioning has been performed in private networks –point-to-point connection with a given pre-allocated capacity –destination-specific: large number of configuration parameters –Implementation: MGW or MGW / edge router  Hose model –first proposed as a flexible model for resource provisioning in VPNs –no individual pipes between nodes but “hoses”, which contain all incoming or outgoing traffic –Advantages: flexibility, ease of specification, multiplexing gain and characterization

15. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt © Ericsson AB 20052005-08-0315 Simulations  What is the actual gain of statistical multiplexing when the traffic is handled as an aggregate rather than as individual pipes?  Simulations were performed with the NS2 network simulator –PCM: CBR UDP application –AMR: two Exp on/off UDP apps.

16. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt © Ericsson AB 20052005-08-0316 Simulations - results  Bandwidth limit for link –PLR 10 -4 –Jitter <5ms  Utilization: gained link bw divided with average bw

17. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt © Ericsson AB 20052005-08-0317 Simulations - results

18. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt © Ericsson AB 20052005-08-0318 Conclusions  Although various mechanisms exist for guaranteeing some QoS level in an IP network there is no particular mechanism that alone could sustain a certain QoS  available mechanisms should be used together so that different mechanisms on packet, flow, and network level complement each other  Justifies also the use of static admission control methods, with which a permanent limit can be set for the traffic that a site can offer to a backbone network

19. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt © Ericsson AB 20052005-08-0319 Conclusions  Pipe vs. hose –flexibility and easy implementation are clearly characteristics of the hose model –overprovisioning factor related to configuration parameters can with high probability be kept under 2 for the hose model –simulations show clearly that the utilization improves when the traffic intensity is increased, but…  Already 250 Erl traffic has utilization rate of ca. 80 % –gain is not necessarily that significant and does not alone make a clear difference between the two models

20. Top right corner for field-mark, customer or partner logotypes. See Best practice for example. Slide title 40 pt Slide subtitle 24 pt Text 24 pt Bullets level 2-5 20 pt © Ericsson AB 20052005-08-0320 Future work  measurements from a real network are needed to validate any simulation results  edge router based pipe model  dynamic resource allocation  optimal routing method for the hose model  domain model: combine best features from pipe and hose models

21. Slide title In CAPITALS 50 pt Slide subtitle 32 pt Questions?