9.3.1 General

24.2813GPPMission Critical Video (MCVideo) signalling controlProtocol specificationRelease 18TS

9.3.1.1 Common Procedures

9.3.1.1.1 MONP MCVideo message transport

In order to participate in a call of an MCVideo group, the MCVideo client:

1) shall send the MONP MCVideo message transported in a MONP MCVIDEO MESSAGE CARRIER message, specified in 3GPP TS 24.379 [40 ], as a UDP message to the multicast IP address of the MCVideo group, on UDP port 8809 (as specified in 3GPP TS 24.379 [40]), with an IP time-to-live set to 255; and

2) shall treat UDP messages received on the multicast IP address of the MCVideo group and on port 8809 as received MONP MCVIDEO MESSAGE CARRIER messages.

The MONP MCVIDEO MESSAGE CARRIER message is the entire payload of the UDP message.

9.3.1.1.2 Session description

One off-network MCVideo session includes one media-transmission control entity.

The MCVideo client shall generate an SDP body for a group call in accordance with rules and procedures of IETF RFC 4566 [2].

The MCVideo client:

1) shall include in the session-level section:

a) the "o=" field with the <username> portion set to a dash;

b) the "s=" field with the <session name> portion set to a dash; and

c) the "c=" field with the <nettype> portion set to "IN", the <addrtype> portion set to the IP version of a multicast IP address of the MCVideo group and the <connection-address> portions set to the multicast IP address of the MCVideo group;

2) shall include the media-level section for audio component of MCVideo consisting of:

a) the "m=" field with the <media> portion set to "audio", the <port> portion set to a port number for MCVideo group, the <proto> field set to "RTP/AVP" and <fmt> portion set indicating RTP payload type numbers;

b) the "i=" field with the <session description> portion set to "audio component of MCVideo";

c) the "a=fmtp:" attribute(s), the "a=rtpmap:" attribute(s) or both, indicating the codec(s) and media parameters of the audio component of MCVideo;

d) the "a=rtcp:" attribute indicating port number to be used for RTCP at the MCVideo client selected according to the rules and procedures of IETF RFC 3605 [3], if the media steam uses other than the default IP address;

3) shall include the media-level section for video component of MCVideo consisting of:

a) the "m=" field with the <media> portion set to "video", the <port> portion set to a port number for MCVideo video of the MCVideo group, the <proto> field set to "RTP/AVP" and <fmt> portion set indicating RTP payload type numbers;

b) the "i=" field with the <session description> portion set to "video component of MCVideo";

c) the "a=fmtp:" attribute(s), the "a=rtpmap:" attribute(s) or both, indicating the codec(s) and media parameters of the MCVideo video;

d) the "a=rtcp:" attribute indicating port number to be used for RTCP at the MCVideo client selected according to the rules and procedures of IETF RFC 3605 [3], if the media stream uses other than the default IP address; and

4) shall include the media-level section for media-transmission control entity consisting of:

a) an "m=" line, with the <media> portion set to "application", the <port> portion set to a port number for media-transmission control entity of the MCVideo group, the <proto> field set to "udp" and <fmt> portion set to "MCVideo"; and

b) the "a=fmtp:MCVideo" attribute indicating the parameters of the media-transmission control entity as specified in 3GPP TS 24.581 [5].