I have a problem with sound quality in the phones connected to Asterisk. The other end of the connection does not seem to be affected. The symptom is a sort of bubbling effect on the sound, quite rapid clipping. When the conversation starts the sound is fine, the effect starts after maybe a minute or so. Both softphones and hand sets show the same symptom.
We are connecting through a 2 Mbit/s SDSL line, not heavily used, to an IAX2 provider. The codec listed first is alaw, followed by ulaw. We’re using the ztdummy driver for timing. Asterisk version is 1.0.1.
We’re just starting out using Asterisk, so if there are any major omissions in the information I should have provided, please bear with me.
Any pointers to docs or other help to debug the problem is appreciated.