The examples in Table 1 and Table 2 are the same as the ones in Transcode G.711 to G.729A but in addition to the transcoding G.711 to G.729A, SBC must also transcode between inband DTMF tones on Carrier 1 and DTMF carried in the RTP stream as specified in RFC 2833 on Carrier 2. Since the G711-DEFAULT Codec Entry is set for inband tones (DTMF Relay: None), there are no changes to the Carrier 1 side provisioning.
On the Carrier 2 side, we need to create a modified version of the Codec Entry G729A-DEFAULT with DTMF Relay set to RFC 2833 and use this modified Codec Entry in the PSP on IPTG1 as indicated below. When RFC2833 is selected on the Codec Entry, the DTMF Remove Digits flag is set by default and the DTMF tones are removed from the Carrier 2 audio stream.
Table 1: Transcode G.711 to G.729A and Convert DTMF PSPs
Configuration | Value | |
---|---|---|
Carrier 1 Media G.711 w/Inband DTMF | Carrier 2 Media G.729A w/RFC 2833 | |
PSP | PSP-Carrier1 | PSP-to-Peer |
Silence Factor | 40 | 40 |
Voice Initial Playout Buffer | 10 | 10 |
TOS | 0 | 184 |
Data Initial Playout Buffer | 50 | 50 |
Codec Entry 1 | G711-DEFAULT | G729A-DEFAULT - RFC2833 |
Codec Entry 2 | <none> | <none> |
Codec Entry 3 | <none> | <none> |
Codec Entry 4 | <none> | <none> |
AAL Payload Size | 47 | 47 |
T.38 No. Redundant Packets | 1 | 1 |
T.38 Low Speed No. Redundant Packets | 1 | 1 |
T.38 Max Bit Rate | 14.4 | 14.4 |
Data Rate Mgt Type | Type 2 | Type 2 |
Honor Remote Precedence | Disabled | Disabled |
P2P Transcode | Conditional | Conditional |
Codecs Allowed This Leg | G.711A, G.711U | (none selected) |
Codecs Allowed Other Leg | (none selected) | G.729 |
RTCP | Not selected | Not selected |
Silence Insertion Descriptor | Take defaults | Take defaults |
Digit Detect Send Enabled | Not selected | Not selected |
Table 2: Transcode G.711 to G.729A Convert DTMF Codec Entries
Configuration | Value | |
---|---|---|
G711-DEFAULT | G729A-DEFAULT - RFC2833 | |
Audio Encoding | G.711 | G.729A |
Fax Tone Treatment | <none> | <none> |
Packet Size | 10 ms | 10 ms |
Fax Treatment Failure Handling | Continue | Continue |
G.711 Law | Law from other leg | None |
Modem Tone Treatment | None | Continue |
Modem Treatment Failure Handling | Continue | RFC2833 |
DTMF Relay | None | Selected |