I am seeing some issues with a provider who has sonus equipment as their UA.
As a result, DTMF does not work with Media Services. I think this is a
pretty well known issue within the FreeSwitch community.

*** from FS wiki
DTMF Problems

If you are having DTMF problems and Sonus *is in your media path*, you
should make sure you are using the latest version of FreeSWITCH. As of
FreeSWITCH revision 10744, FreeSWITCH auto-detects Sonus end-points and
applies a hack to "fix" the issue. The hack is described as follows (from
switch_types.h):

Sonus wrongly expects that, when sending a multi-packet 2833 DTMF
event, the sender should
increment the RTP timestamp in each packet when, in reality, the
sender should send the
same exact timestamp and increment the duration field in the 2833
payload. This allows a
reconstruction of the duration if any of the packets are lost.

final_duration - initial_timestamp = total_samples

However, if the duration value exceeds the space allocated (16 bits),
the sender should
increment the timestamp one unit and reset the duration to 0.

Always sending a duration of 0 with a new timestamp should be
tolerated but is rarely
intentional and is mistakenly done by many devices. The issue is that
the Sonus expects
everyone to do it this way instead of tolerating either way. Sonus
will actually ignore
every packet with the same timestamp before concluding if it's DTMF.

Note that the version of FreeSWITCH which has this patch auto-detects Sonus,
so you don't need to configure anything.

***

Can someone give me an indication if thus patch is in the sipx current build
or not? If not, does it make sense to include it?





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