We have an IAX2 trunk to a partner company. Whenever we call them over this (or they call us), the volume from us to them is very low.
All other calls, i.e. general SIP trunks calls are perfectly OK for both companies in both directions.
Any ideas where to start troubleshooting ?
Have you tried fiddling with the VOLUME(TX/RX) function in the dialplan for IAX calls?. Are you using the same codec for both SIP and IAX calls?
[quote] -= Info about function ‘VOLUME’ =-
Set the TX or RX volume of a channel.
The VOLUME function can be used to increase or decrease the ‘tx’ or ‘rx’ gain
of any channel.
Must be ‘TX’ or ‘RX’.
p: Enable DTMF volume control