I have a problem with the Grandstream DP715_US when used with Asterisk version 13.18.3 on Ubuntu 18.04. If I place a call to the DP715 and then place that call on hold the hold music is choppy. If I hang up while the call is on hold the music clears up and plays perfectly. My asterisk box will then ring the DP715 to remind me that I’ve got a call on hold. If I pick up the call and then place it back on hold the hold music again becomes choppy. I’ve tried the same thing with the Zoiper 5 softphone and the hold music works perfectly. All that make me think that the issue lies with the DP715.
I found a similar post over on ServerFault (https://serverfault.com/questions/811671/asterisk-music-on-hold-stuttering) in which the root cause of the problem was described like this: It turned out, that the client softphone was sending concurring RTP streams (with no sound, i.e. silence) that was mixed up somehow and thus causing the stuttering. I’m wondering if perhaps something similar is going on with the DP715?
I’ve found an earlier post describing the same problem on the Grandstream site (https://forums.grandstream.com/t/choppy-hold-music/12340) but to date no solution has been offered. I’m all up to date on the DP715 firmware and I don’t think any new firmware is forthcoming. So, if possible, I need a configuration fix for either the DP715 phone or my Asterisk box.
Any help most appreciated!