Wouldn’t it be better to allow the two FreeSWITCH boxes to talk directly to each other for calls between them? Eliminate the middle man and perhaps this and other problems disappear?

https://freeswitch.org/confluence/display/FREESWITCH/IMT

Bote

From: Podrigal, Aron
Sent: Thursday, 19 March, 2015 12:10
Subject: [Freeswitch-users] DTMF missing digits

I am experiencing problems with sonus dtmf. I tried setting different parameters related to the RTP BUGS listed in switch_types.h but it did not seem to fix the problem.

I have freeswitch ----> [carrier(sonus), ...]  -----> freeswitch

freeswitch sends the following digits to our carrier, and is received by the other end (also a freeswitch) missing the digits marked in black.

pcap shows the missing digits as being part of the previous packet, so two 1's becomes one 1 with the duration sum of two.

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What are the relevant parameters I should set?