Is anybody else having trouble with T38 -> g711 gateway with either v1.6 or latest master?  Initially I thought my problems might have been limited to calls bridging to mod_freetdm (i.e. T38 in -> PRI out), but today I was able to reproduce the problem using SIP only.

 

I entered a Jira on the issue yesterday, but was hoping that more eyeballs on the problem might reveal something.

 

https://freeswitch.org/jira/browse/FS-9008

 

Not sure if everyone can read Jira tickets, so here's the gist of what I can see happening:

 

- FS1 txfax to FS2

- FS2 sets the following parameters, then bridges call to FS3

** fax_enable_t38_request=true

** execute_on_answer=t38_gateway self

- FS3 answers, then calls rxfax

- bidirectional g711 between FS1/FS2 and FS2/FS3

- FS1 sends T38 reinvite to FS2

- FS2 responds 100 Trying

- FS2 starts sending T38 packets to FS1 (unexpected), while still sending g711 to FS3 (expected)

- 39 seconds later FS2 sends BYE to FS1, but using a new CSeq/branch not seen elsewhere in either leg (?)

- FS2 finally responds to T38 request from FS1, but with 486 Busy Here instead of 200 OK

- FS2 sends repeated BYE to FS1 (e.g. at 1,2,4 seconds)

 

Thanks!

 

Dave.