ts_127007v110800p

3GPP TS 27.007 version 11.8.0 Release 11
275
ETSI TS 127 007 V11.8.0 (2013-10)
The communication client in the MT shall take into account SDP a-line rtpmap and fmtp attributes when
negotiating media. Which other attributes in media level SDP a-lines are taken into account by the
communication client is implementation specific.
Partial SDP m-lines include nothing but a media type.
For every media either an SDP m-line or a partial SDP m-line must be provided.
SDP m-lines indicate that the described media is encoded/decoded outside the MT.
Partial SDP m-lines indicate that the described media is encoded/decoded by the MT. When negotiating media
the MT adds payload information to the partial SDP m-line.
The communication client in the MT shall use the provided SDP line information when negotiating media. The
communication client shall add other SDP lines required for negotiating media.
Example:
+CDEFMP=,"m=audio%x0D%x0Am=video 98%x0D%x0Aa=rtpmap:98 L16/16000/2"
Implementation
Optional.
13.2.5 Control and modify media description +CCMMD
Table 13.2.5-1: +CCMMD parameter command syntax
Command
+CCMMD=,[,]
Possible response(s)
+CCMMD
+CCMMD=
Description
This command allows control of the media used in a multimedia call. The command can be used to initiate modification
of the media of an ongoing call, to accept / reject incoming changes in media or to accept / reject the media for an
incoming call.
When matches the index of an ongoing call, the TA/MT will attempt to add or remove media to the call by
triggering an SDP renegotiation over the SIP protocol.
When =1, the set command requests an unconditional change the media of the call to that described
by .
When =2, the set command proposes a change of media to that described by , to which
the remote party has to respond before the media of the call is changed. The response from the remote party will be
indicated in a +CMCCSI unsolicited result code. If the remote party accepts the change of media, the
value in +CMCCSI will be set to 3. If the remote party rejects the change of media, will be set to 4. In
both cases the value in +CMCCSI will describe the currently active media of the call (if any).
If the remote party unconditionally changes the media of the call, this will be indicated in a +CMCCSI unsolicited result
code, with =1 and containing the updated (and now active) media description.
If the remote party proposes to change the media of an ongoing call, this will be indicated in a +CMCCSI unsolicited
result code, with =2. The set command should be used to respond to the proposal, either accepting it
by setting =3, or rejecting it by setting =4.
When the MT receives an incoming call from a remote party, the +CMCCSI unsolicited result code will be sent to the
TE with =2. This proposed media for the new call should either be accepted, (as described above) or
it should be rejected and a new media should be proposed using the set command with =2.
ETSI