Hi,
I have a trace with RTP packets containing an AMR
payload. The problem is that Ethereal shows strange information. Is it
possible that the payload is not following the rfc 3267 recommendations?. What
I need to know is how the payload header is built, and where are the
speech bits. Below there are some sample RTP packets. Could anybody help
me?
80 60 3b 51 00 00 54 b0 55 dd 3e d2
b7 2f a4 d6 82 40 9d 09 89 79 3c 7f 80 2a be 5a e2 07
08 00 10 80 01 c8 dc b0 03 12 82 74 02
------------------------------------------------------
-------------------------------------------------------------------------------------------------------------------------------------------
RTP header (seems
OK)
AMR (where is the
payload header according to RFC 3267?? where are the speech
bits?)
Ethereal shows the following:
CMR = PDC-EFR-SID
Reserved = 7
Payload table of contents:
(Empty, ethereal shows nothing)
Another example:
80 60 3b 52 00 00 55 50 55 dd 3e d2
07 86 60 5e b1 0e 11 70 31 67 fd af aa 60 ea 10 02 00
a2 c3 10 19 63 22 c9 a9 44 20 7a 63 c6
Ethereal shows the following:
CMR = AMR 4,75 kBits/s. (0)
Reserved = 7
Payload table of contents:
(Empty, ethereal shows nothing)
This trace has been obtained in a H.323 call between a 3G phone and
a H.323 endpoint with AMR codec support through a 3G-IP gateway. I can send
the trace file (20 kb, zipped if it's necessary).
Thanks in
advance,