Version 6.2 149 December 2010
SIP Release Notes 3. Known Constraints
6. High Transcoding probability (devices other than MSBG always perform transcoding).
Product
MP-11x MP-124
Mediant 600 Mediant 1000
Mediant 800 MSBG Mediant 1000 MSBG
Mediant 2000
Mediant 3000/TP-6310 Mediant 3000 HA/TP-6310
Mediant 3000/TP-8410 Mediant 3000 HA/TP-8410
3.2 Media Constraints
This release includes the following known voice, RTP and RTCP constraints:
1. The RTP payload size on RTP forwarding in the SBC application cannot exceed 1,000
bytes. A workaround for this constraint is to reduce the MTU to less than 1,000 bytes
on remote endpoints.
Product
MP-11x MP-124
Mediant 600 Mediant 1000
Mediant 800 MSBG Mediant 1000 MSBG
Mediant 2000
Mediant 3000/TP-6310 Mediant 3000 HA/TP-6310
Mediant 3000/TP-8410 Mediant 3000 HA/TP-8410
2. If the initial transcoding session has one side using a narrowband coder (e.g. G.711),
modifying the transcoding connection to wideband coders still results in narrowband
voice quality. A workaround for this constraint is to ensure that the entire session uses
wideband coders.
Product
MP-11x MP-124
Mediant 600 Mediant 1000
Mediant 800 MSBG Mediant 1000 MSBG
Mediant 2000
Mediant 3000/TP-6310 Mediant 3000 HA/TP-6310
Mediant 3000/TP-8410 Mediant 3000 HA/TP-8410
