Nortel Media Gateway 3200 User Manual page 101

H.248 User's Manual
m=audio 4020 RTP/AVP 0
a=ptime:20
a=silencesupp:off - - - -
a=cdsc: 2 audio RTP/AVP 0 18 4
a=cpar: a=fmtp:18 annexb=yes
a=cpar: a=rtpmap:4 G723/8000/1
a=cpar: a=fmtp:4 bitrate=6.3;annexa=yes
a=cpar: a=ptime:20
a=cpar: a=silencesupp:off - - - -
}}}}}
In Example 2, the local was requested to use both audio and image, but the remote
supports only the audio and parts of the coders. The reply returns the image as a capability
in the session level and the fully supported coders in the media level.
7.2.3.3 Mapping Payload Numbers to Coders
The table below shows the default mapping between payload numbers and coders when
the dynamic payload assignment is not used. Note that this is a general table and only the
DSP template that is loaded to a MG 3200 defines which coder is supported on this MG
3200.
These values can be overridden by the external CoderTbl.
Table 32: MEGACO Mapping Payload Numbers to Coders
Default Payload
Number
0
2
4
80
8
15
18
35
36
38
39
40
41
42
43
44
Version SN09
Encoding Name
"PCMU"
"G726-32"
"G723"
"G723"
"PCMA"
"G728"
"G729"
"G726-16"
"G726-24"
"G726-40"
"X-G727-16"
"X-G727-24-16"
"X-G727-24"
"X-G727-32-16"
"X-G727-32-24"
"X-G727-32"
Coder
G711Mulaw
G726_32
G723 (High)
G723 (Low)
G711Alaw_64
G728
G729
G726_16
G726_24
G726_40
G727_16
G727_24_16
G727_24
G727_32_16
G727_32_24
G727_32
101
7. Standard Control Protocols
October 2006