We have a strange problem with music on hold in our VoIP/SIP setup. When an inbound call is put on hold (either because of a transfer or by locally holing the call by pressing the pause button in jitsis call window), the music is stuttering/stammering in various degrees (i.e. sometimes the music plays well, sometimes it is just an annoying sound mess interrupted by silence. The quality of playback even changes when holding and unholding the same call several times.)
We use the latest stable 32 bit version of Jitsi on Windows 7x64 clients.
The SIP server is Asterisk 13.7.2 inside a VM (asterisk.conf has internal_timing unset, defaults to "yes"). The MOH files are WAV mono 8000 Hz 16bit PCL encoded.
The problem only occurs with Jitsi as a client when the audiosystem is either WASAPI or PortAudio. Using Audiosilence (for testing), the issue is gone. Other softphones (3CXPhone) or OSs (Linux) also work.
It is unlikely, that the asterisk server is (alone) to blame, because other music files play perfectly well (for voicemail and queues). Even the same (working) files when used for MOH are not played back well.
We even tried different codecs (ULAW, ALAW, GSM) without any notable differences.
Any hints or suggestions on this issue are welcome. The callers are really getting angry on the annoying sounds they hear when put on hold.
Kind regards and thanks in advance,