Nortel Media Gateway 3200 User Manual page 91

H.248 User's Manual
7.2.2.8 Mediation
Mediation in H.248 connects two ephemeral terminations. This operation can be used by a
Call Agent to connect users with different coders or to connect two types of users, such as
ATM and RTP. The mediation operation requires up to two DSPs according to the following
rules:
When both users use the same coder, no DSP is allocated.
When one user uses a G.711, one DSP is allocated for the other user.
When both users use non-G.711 and different coders, two DSPs are allocated.
The mediation is created with a simple H.248 ADD command, with two ephemeral
terminations, as shown in the following example:
MEGACO/1 [10.10.0.70]; Connect the streams,
Transaction = 2 {
Context = $ {
v=0
m=audio $ RTP/AVP 0
c=IN IP4 $
v=0
m=audio 4000 RTP/AVP 0
c=IN IP4 10.2.229.19
v=0
m=audio $ RTP/AVP 4
c=IN IP4 $
v=0
m=audio 4010 RTP/AVP 4
c=IN IP4 10.2.229.19
}}}}}
This example connects two RTP streams, one uses the G.711 coder and the other uses
the G.723 coder.
7.2.2.9 CAS/R2 Support in H.248
The CAS/R2 trunk protocols are supported in H.248 by using the 'bcas' package defined in
H.248.25, the 'icas' and 'casblk' packages defined in H.248.28 and 'icasc' package defined
in H.248.29
Version SN09
Add =
rtp/jit=70 },
Local {
},
Remote {
}
},
Add = $ {
rtp/jit=70 },
Local {
},
Remote {
$ {
Media {
LocalControl {
Mode = SendReceive,
}
Media {
LocalControl {
Mode = SendReceive,
91
7. Standard Control Protocols
October 2006