1 Kommunikatsiooniteenuste arendus IRT0080 Loeng 8/2008 Avo Ots telekommunikatsiooni õppetool, TTÜ raadio- ja sidetehnika inst.

2 Kasutuskava muutus One computer/phone, many users One computer/phone, one user Many computers/phones, one user anywhere, any time any media right place (device), right time, right media ~ ubiquitous computing  embedded VoIP mainframe era home phone party line PC era cell phone era

3 Meediateenuse tagamine (IMS) Teenuse kasutus Teenuse haldus Juurdepääs

4 Session Initiation Protocol (SIP) Originally specified in RFC 2543 (March 1999) RFC 3261, new standards track released in June 2002 An application-layer control signaling protocol for creating, modifying and terminating sessions with one or more participants A component that can be used with other IETF protocols to build a complete multimedia architecture (e.g. RTP, RTSP, MEGACO, SDP)

5 SIP Architecture Client-server in nature Main entities: –User Agent –Proxy Server –Redirect Server –Registration Server –Location Server

6 S I P sõnumid (RFC3261) INVITE – meediasessiooni algatamise kutse saatmine kasutajale. ACK – kinnitus INVITE sõnumiga sessiooni algatamise kutse saamise kohta. BYE – meediasessiooni lõpetamine. CANCEL – pooleliolevate päringute katkestamine (ei katkesta pooleliolevat meedia-sessiooni). OPTIONS – serveri võimaluste küsimine. REGISTER – kasutaja registreerumine SIP serveris

7 Lisandused /kohe!!/ PRACK – esialgne kinnitus (RFC 3262) SUBSCRIBE – sündmusest teavitamiseks registreerumine (RFC 3265) NOTIFY – kasutajate teavitamine sündmusest (RFC 3265) PUBLISH – serveri teavitamine sündmusest...

8 SIP Session Establishment and Call Termination Application

9 Call Redirection Using a Redirect Server

10 Call Proxy Scenario

11 Proxy/Redirect Servers and UA SIP User Agent (Caller) SIP Proxy Redirect Server SIP User Agent (Caller) SIP Proxy Location Service 1 2, Non-SIP Protocol 5,6

12 Design and Implementation User Agents (Clients) RTPRTCP UDP UASUAC VideoAudioText Messaging QoSQoSSignaling Media Transport

13 Lõpulingid (8) king voicexml.html m ol _Protocol

14 Windows Messenger SIP-based Core Features: Presence and contact list management Instant Messaging Voice and Video Data collaboration and File transfer PC to Phone Administrative Policies to enable/disable features Acoustic Echo Cancellation in software

15 Windows Messenger Microsoft.Net SIP server or enterprise SIP server Can not go point-to-point using IP addressing- needs proxy server Microsoft Live Communications Server (LCS) is their proxy server