Bad Audio Quality VOIP to VOIP?

[Thona]

Not sure who is respionsible and what to do.

We have a test installation of 3cx running with a customer of ours They docall center work, currently running the free license as a trial.

In general, things are pretty fine. Sometimes, though, the audio quality SUCKS. Seriously. In every such case we could trace it down to both sides using VOIP, and the other side now having issues "with phone in general" (i.e. they are not aware of a general bad line quality).

For a call center this is pretty bad, and I am wondering if anyone else has experienced this and could give some tips about how to handle this? We do not use direct SIP, but a voip provider, naturally, to a phone system - so the call goes 3cx -> voip provider -> pstn -> voip provider -> other side.

Any tips how to handle this? I can only assume it is not bandwith and other stuff as ll other connections work with actually very good quality.

 

[Thona]

That actually is why I ask.

The scenario handles lots of calls on currently 4 operator lines. Incoming, outgoing.

Normally quality is really good. I mean, not stellar, but this is PHONE anyway.

Sometimes is is miserable.

In all cases we could verify it, miserable is when the other side ALSO has a VOIP/PSTN gateway system.

As long as the other side is "normal" (and possibly in many cases the other side is using VOIP, too) the quality is absolutly perfect.

Just sometimes it is nearly not understandable, and - well - we tracked all these caes to VOIP to the other side (or no information, obviously).

CPU . NO clue - need to get logs written

Bandwidth - not an issue at all. We have dedicated 8mb, never utilized more than 75% in spikes, QOS on edge routers - and as I said: no issues normally.

We are in fact really pleased with the quality normally.

I am also not sure I am blaming 3cx here - it possibly is a generic issue of either interoperability 8hard to get by - try getting some person on the othe rside telling you what exactly they use), or something of our VOIP provider. But I would like to nail it down a little more.

 

[Nebula]

Do you know if the codec's being used are consistent throughout the chain? If a call is compressed and decompressed several times between the endpoints this can cause quality issues.especially if different codecs are in use at various points in the chain.

 

[Henk]

Can you provide some examples for example:

H--e--ll---o
Hello <long wait for reply> Hello (pretty much like the old days).

If you talk about call quality, is it related to the crispness or the stuttering?

H.