Bad Audio in One Direction


#1

I am using AAH and SIP to Broadvoice.

During the course of a phone call, the audio coming to me is usually perfectly clear, but periodically the people I am talking to complain that the audio is broken up (often described as sounds like I am under water). It comes and goes … during the course of a one hour call it could happen 2 or 3 times for a few minutes in duration each time.

My first thought was upstream bandwidth. But I periodically run various online tests and see 300-400kbps upstream even when I have a call in progress (over 400 without a call in progress) … so that doesn’t seem to be it. (Although this isn’t really definitive).

Anybody have any thoughts or suggestions?

Thanks /lss


#2

I experience a similar problem but the other way. In other words, my conversation partner can hear me very well but I sometimes get bursts of dropped packets and delay. I think this has to do with the bandwith at their end and also with cpu power on the soft phone at their end. I’m talking of an extension to extension call with one extension being on the LAN and the other in another country about 20 hops away. If the calls are “close” (i.e. few hops) this doesn’t usually happen. I would run some tests to measure the end to end bandwith and the cpu usage on both ends.


#3

there are a lot of reasons, but upstream bandwidth is not everything. You can get burst of downstream bandwidth (even if you have a big downstream pipe) that can do this if you don’t have anything helping to throttle the flow control of potential tcp sessions and other traffic. And of course it can be on either end if both are using VoIP. If you aren’t using any sort of device to help QoS on your end, you should try something and see if it helps. For a small environment like hope or home office, something like a Dlink DI-102 can help substantially, or a SOHO router with QoS built in, preferably something like Speedstream (similar to what DI-102 is using). Or you can go with something more sophisticated that can do this but you descriptin sounds more like residential/SOHO and these other options keep it priced in that ball park.

p


#4

Some interesting thoughts but I am not sure they are focusing in on the problem. First… Only one side is using VoIP (me) so I know it is not the other side. Second, I have held a few extension-to-extension calls and they are perfectly clear, so it doesn’t appear to be my PBX, specifically.
Finally, with respect to the downstream bandwidth … I don’t think so. My wife and I are the only users of the network and I have run a number of these tests when she was out :smile:

I have been pondering the QoS issue for a while, but I don’t believe it addresses the issue at hand.

Thanks for the thoughts though.