[asterisk-users] 0005162: RTP Packetization : Few questions

[Dan Austin]

>>2006-08-31 22:11:22 WARNING[1278]: frame.c:1072 
>>ast_codec_pref_getsize: Framing not set for codec alaw, using 
>>default 20
> 
> As far as the above is concerned I have the following:

> I am using Asterisk 1.2.10, patched with this patch for 1.2.10.  
> I have 2 * boxes.  They call each other over SIP, and I have in 
> sip.conf on both boxes

> autoframing=yes
> disallow=all
> allow=g729:80

> When A calls B, it sets ptime:80.

> On B I see this:
> We're at 192.168.0.64 port 11004
> Adding codec 0x100 (g729) to SDP
> Sep  7 18:16:16 WARNING[5529]: frame.c:1072 ast_codec_pref_getsize: 
> Framing not set for codec g729, using default 20 and ptime:20

> So B is setting packetization to 20, when it should be 80, and is 
> not respecting autoframing.

> I have tried this with reinvites=yes and no, and autoframing=yes and
> no, still the same.

The autoframing patch forgot to remove an earlier check for 'ptime'
in the SDP that would cause chan_sip to ignore the ptime value.

I am working on trunk, so the line numbers may not match up, but
near line 4748 you will should find this block of code:

} else if (!strncasecmp(a, "ptime:", (size_t) 6)) {
                                if (debug)
                                        ast_verbose("Got unsupported
a:ptime in SDP offer \n");
                                breakout = TRUE;

Simply comment out the breakout = TRUE; line like this.

} else if (!strncasecmp(a, "ptime:", (size_t) 6)) {
                                if (debug)
                                        ast_verbose("Got unsupported
a:ptime in SDP offer \n");
                                /* breakout = TRUE; */

That fixes up autoframing in my tests, if it works for you, I will
prepare a proper patch.

Dan