We have multiple SPA2102s configured with T38 enabled and a 2811 Router
The ATAs are configured as expected for Faxing... (echo disabled, very high jitter, Fax passthrough Re-Invite)
The router is also configured to try T38 and failover to G711.
We have a sip server sitting in the middle of the Router and the ATA that routes the call and transparently bridges the T38 media so that the T38 data is being exchanged directly between the ATA and the Router (The router is a PSTN termination gateway with a PRI behind it).
As stated in the subject the Fax machines are able to receive faxes successfully, but Sending from the Fax machines fails most of the time...
Any pointers would be really helpful.