Support Services &IP Multimedia Subsystem (IMS)

T-110.7111 - Internet Technologies for Mobile Computing

Name – Koushik AnnapureddyStudent Number – 84973F

Support Technologies

IP Multimedia Subsystem (IMS)

Session Initiation Protocol (SIP)

IP Television ( IPTV )

Security and Trust

Charging and Billing

Why IMS ? 3G Networks have a Packet Switched Domain to perform

data communications.

User can surf the content and can do anything as in the case of ISDN,DSL.

Requirements –

Quality of Service

Charging

Faster Development of Services ( Reusable Components )

IMS Architecture

IMS as a Business model. Provides Integrated services to users. Operators want to use services

developed by third parties, combine them, integrate them with services they already have, and provide user with completely new service

Protocols

Keeps signaling and media paths separate.Access – independent – WLAN,ADSL,HFC,3G..

SIP – Client – Server model (SMTP, HTTP). Can use CGI and Java Servlets.

AAA (Authentication, Authorization and Accounting) – Diameter.

COPS , RTP , RTCP

Benefits of IMSOperators : Competitive advantages.Reduced time to marketLower deployment costs.Value chain control.

End Users: Services & interaction.Integrated rich media ( text,audio,video ) in

the same call.Mobile Fixed InternetworkingPersonalized communications.

SERVICES AND APPLICATIONS IN IMS

Multi-Device Video StreamingIP TVPrioritized PresenceInteractive ApplicationsVideo ConferencePush to Talk Over Cellular (PoC)

IPTV Today’s solutions –Web TVP2P TV

Need for IMS in IPTV solutions – Framework for IPTV service control, user profiles, charging

(pay per view ) , QOS. Convergence of IMS and TV services Access to TV services through different bearers ( DSL,

UMTS , WLAN , DVB-X ) AAA Services

IPTV Framework via IMS

What is SIP ?SS7 is to the mobile telephony, SIP is to the Internet. Create , Modify and Terminate Sessions( Text, Voice,

Video ).

User location User capabilitiesUser availabilityCall setupCall handling

SIP Entities

User Agents - User Agent Client ( UAC ) User Agent Server (UAS)

Network Servers – Proxy Server Redirect Server Registrar

Presence, Instant Messaging and Voice

Charging & BillingAccounting –

Capacity & Trend Analysis Cost Allocation Auditing Charging and Billing

IMS uses the Diameter protocol to transfer the accounting information that charging in IMS is based on.

CSCF, GGSN inform the charging system about media activity during those sessions.

IMS Event based Charging – Offline event based Online event based

Session Based Charging – Offline Session based Online Session based

Security and Trust

IMS is an overlay network on top of existing network protocol stack, specifically IP, and uses SIP as a generic building block.

IP – Route hijacking, denial of service, source address spoofing.

IMS inherits the security issues of IP and SIP .

Security Threats

Toll fraud Denial of ServiceSession hijackingAddress spoofingAuthentication and End – End SecurityPrivacyMalwareEnergy Consumption

References 1) Ericsson. IMS – IP Multimedia Subsystem. White Paper,

October 2004.2) G. Camarillo and M. Garcia-Martin. The 3G IP multimedia

subsystem(IMS): merging the Internet and the cellular worlds. Wiley, 2nd edition,2006.

3) R. L. Chen, E. C. Su, V. S. Shen, and Y.-H. Wang. Introduction to IPMultimedia Subsystem (IMS), Part 1: SOA Parlay X Web services. IBM developerWorks, September 2006.

4) Kuhn, R.: Security considerations for voice over IP systems.5) IP Multimedia Subsystem (IMS); stage 2. 3GPP TS 23.228,

Release 7 2006.6) H. Schulzrinne, G. Camarillo, A.R. Johnston, J.Peterson, R.

Sparks, M. Handley and E. Schooler. SIP: Session Initiation Protocol. IETF RFC 3261, June2002.

Thank you Any questions