[Asterisk-Users] RE: iLBC

[Juha Heinanen]

Alan Duric writes:

 > the problem seems to be the following:
 > - Kphone is using iLBC implementation based on draft draft-andersen-ilbc-01
 > and it worked well with implementations based on
 > draft-ietf-avt-ilbc-codec-00, which followed it (that was the actual one at
 > the time of SIPiT interop event). However, it seems that there's problem
 > with backwards compatibility of current draft draft-ietf-avt-ilbc-codec-01
 > (which is used by Asterisk implementation and will go for the WG last call)
 > against draft-andersen-ilbc-01 implementations. We have tested it very
 > carefully against draft-ietf-avt-ilbc-codec-00, and it worked well.

alan,

we changed kphone so that now it is compatible with
draft-ietf-avt-ilbc-codec-01, but i don't think that that is really
the issue.

according to raft-ietf-avt-ilbc-codec-01, rtp payload is either 38 or 50
bytes, right?  kphone is sending 50 byte payloads, but * seems to expect
52 byte payload:

WARNING[14350]: File codec_ilbc.c, Line 141 (ilbctolin_framein): Huh?  An
ilbc frame that isn't a multiple of 52 bytes long from RTP (50)?

if our interpretation of 50 byte payload size is correct, then it is *
that is screwing this up if it is expecting to receive 52 byte payloads.

-- juha