Call hangs after 1 second

Happened on M2. Problem was with G729 codec.

Search for Freeswitch LegB log. It showed:

[ERR] switch_core_io.c:1445 Codec G.729 encoder error!

LegA log and pcap showed that BYE is sent from M2 after 0.000x seconds when call was ANSWERED.

Solution - use only G729 or only another codec to avoid transcoding.