With a large number of faxes sent (at the same time 15 channels), I often get errors like::
2019-04-17 09:36:37] WARNING[8946]: chan_iax2.c:3592 attempt_transmit: Max retries exceeded to host 127.0.0.1 on IAX2/418521-5369 (type = 6, subclass = 11, ts=70007, seqno=22)
[2019-04-17 09:36:46] WARNING[8945]: chan_iax2.c:3592 attempt_transmit: Max retries exceeded to host 127.0.0.1 on IAX2/418529-8000 (type = 6, subclass = 11, ts=70009, seqno=22)
for Elastix 4, I corrected in the source channels/chan_iax2.c
-static int max_retries = 4;
+static int max_retries = 12;
and compiled chan_iax2.so And it helped me a lot.
Someone did this for Issabel asterisk 13?
Someone can make adjustments to the source code Issabel asterisk 13?
and rebuild chan_iax2.so with a new variable max_retries = 12 ?