1. Speaker：Wenping Zhang Date：2008/01/23
Message Session Relay Protocol Adaptation for Interactive Connectivity Establishment (ICE) draft-niemi-simple-msrp-ice-00
Speaker：Wenping Zhang
Date：2008/01/23

2. Outline Introduction Overview of Operation Generating SDP offer
Generation SDP Answer
Reference

3. Introduction
The Message Session Relay Protocol (MSRP) defines a mechanism for transmitting a series of related instant messages in the context of a session.
This session is established using a separate session negotiation protocol, such as the Session Initiation Protocol (SIP) , and the Offer/Answer Model with the Session Description Protocol (SDP) .

4. Overview of Operation
To initiate an MSRP session, the initiator collects ICE candidates, each of which are one of three types:
An active candidate for which the agent will attempt to open a TCP connection
A passive candidate for which the agent will be in passive mode and only listen for incoming connections
Simultaneous open candidate, for which the agents will attempt a TCP simultaneous open

5. Generating SDP Offer v=0 o=jdoe 2890844526 2890842807 IN IP4 s=
c=IN IP
t=0 0
a=ice-pwd:asd88fgpdd777uzjYhagZg
a=ice-ufrag:8hhY
m=message 7746 TCP/MSRP *
a=accept-types:text/plain
a=path:msrp:// :7746/asd88fgpdd777uzjYhagZg;tcp
a=candidate:1 1 tcp-so typ local
a=candidate:2 1 tcp-pass typ local
a=candidate:3 1 tcp-so typ srflx raddr rport 12534
a=candidate:4 1 tcp-act typ srflx raddr rport 12534
a=candidate:5 1 tcp-pass typ srflx raddr rport 12534
a=candidate:6 1 tcp-pass typ relay raddr rport 12534

6. Generating SDP Answer v=0 o=jdoe 2890844526 2890842807 IN IP4 s=
c=IN IP t=0 0
a=ice-pwd:asd88fgpdd777uzjYhagZg
a=ice-ufrag:8hhY
m=message 7746 TLS/MSRP
a=setup:holdconn # Also useless...
a=connection:existing
a=fingerprint:SHA-1
4A:AD:B9:B1:3F:82:18:3B:54:02:12:DF:3E:5D:49:6B:19:E5:7C:AB
a=accept-types:text/plain
a=path:msrp:// :7746/asd88fgpdd777uzjYhagZg
a=candidate:1 1 tls-so typ local
a=candidate:2 1 tls-act typ local
a=candidate:3 1 tls-pass typ local
a=candidate:4 1 tls-so typ srflx raddr rport 12534
a=candidate:5 1 tls-act typ srflx raddr rport 12534
a=candidate:6 1 tls-pass typ srflx raddr rport 12534

7. Reference
Message Session Relay Protocol Adaptation for Interactive Connectivity Establishment (ICE)
RFC4975 The Message Session Relay Protocol