Backward jump in IAX2 miniframes timestamping

Hi all,

a collegue reported to me a strange behaviour in Asterisk, he was using a Asterisk 1.2.13 to make SIP to IAX calls, he made a call, after a while he pressed HOLD button in SIP phone and MusicOnHold started in IAX side for a X time interval.

At this point he pressed again HOLD button in SIP phone to un-hold the call, and he started speaking, but no voice was heard from IAX side for a X time interval!

Then my collegue used WireShark to take some packets capture. And here is the trouble, when he pressed HOLD to un-hold and started speaking his voice actually reached the IAX side but with the same timestamps before the music on hold!!! And so voice was discarded as old voice.

I can send the trace to everyone needs it, as you can see there is a sudden backward jump in voice timestamping.

No.  Time      Source       Destination   Protocol  Info

2857 58.607095 10.10.10.2   10.10.10.1    IAX2      Mini packet, source call#22, timestamp 58620, Raw A-law data (G.711)
2858 58.627681 10.10.10.2   10.10.10.1    IAX2      Mini packet, source call#22, timestamp 34056, Raw A-law data (G.711)
2859 58.647984 10.10.10.2   10.10.10.1    IAX2      Mini packet, source call#22, timestamp 34096, Raw A-law data (G.711)

Asterisk address is 10.10.10.2 of course and 10.10.10.1 is a IAX2 gateway.

Please let me know if this bug is already known and may be fixed in developping version. Any feedback will be very appreciated.

Thank you for your attention to this report,

Antek Company R&D Branch