Version 7.2 389 Mediant 1000B Gateway & E-SBC
User's Manual 19. Coders and Profiles
Coder Name Packetization Time
(msec)
[1] 10, [2] 20, [3] 30, [4] 40,
[5] 50, [6] 60, [8] 80, [9] 90,
[10] 100, [12] 120
Rate (kbps) Payload
Type
Silence
Suppression
EVRC
evrc
[12]
20 (default), 40, 60, 80,
100
[91] Variable
(default)
[1] 1/8
[94] 1/2
[95] Full
Dynamic
[0] Disable
[1] Enable
iLBC
ilbc
[19]
20 (default), 40, 60, 80,
100, 120
[39] 15 (default) Dynamic
(default 65)
[0] Disable
[1] Enable
30 (default), 60, 90, 120 [34] 13
Transparent
transparent
[7]
10, 20 (default), 40, 60,
80, 100, 120
[90] 64 Dynamic
[0] Disable
[1] Enable
T.38
t-38
[4]
N/A N/A N/A N/A
T.38 Over RTP
t-38-over-rtp
[43]
N/A N/A Dynamic
(default 106)
N/A
19.2 Configuring Allowed Audio Coder Groups
The Allowed Audio Coders Groups table lets you configure up to 10 Allowed Audio Coders
Groups for SBC calls. For each Allowed Audio Coders Group, you can configure up to 10
audio coders. The coders can include pre-defined coders and user-defined (string) coders
for non-standard or unknown coders.
Allowed Audio Coders Groups restrict coders for SIP entities. Only coders listed in the
Allowed Audio Coders Group (i.e., allowed coders) that is associated with the SIP entity
can be used. If the coders in the SDP offer ('a=rtpmap' field) of the incoming SIP message
are not listed in the Allowed Audio Coders Group, the device rejects the calls, unless
transcoding is configured, whereby "extension" coders are added to the SDP, as described
in Coder Transcoding on page 619. If the SDP offer contains some coders that are listed in
the Allowed Audio Coders Group, the device manipulates the SDP offer by removing the
coders that are not listed in the Allowed Audio Coders Group, before routing the SIP
message to its destination. Thus, only coders that are common between the coders in the
SDP offer and the coders in the Allowed Audio Coders Group are used. For more
information on coder restriction, see ''Restricting Audio Coders'' on page 618.
For example, assume the following:
The SDP offer in the incoming SIP message contains the G.729, G.711, and G.723
coders.
The allowed coders configured for the SIP entity include G.711 and G.729.
The device removes the G.723 coder from the SDP offer, re-orders the coder list so that
G.711 is listed first, and sends the SIP message containing only the G.711 and G.729
coders in the SDP.