Any fundamental issues that cause VOIP issues?
 

Hi everyone

I am trying to help a friend solve a VOIP issue. We both have the same VMB 200Mb with the same Hitron router in modem mode going into the same Draytek router. We both have the same hosted VOIP system (Horizon Unlimited), but one subtle difference is that I have an 'assured' connection for the VOIP system (basically just an ADSL connection), whereas he is trying to use his Virgin connection for this.

The relevance of the above is that we have been able to test the same setup on a different Virgin connection, to rule out the connection itself as being the issue. The issue is that when a second phone rings, the call breaks up. Initially it seemed very likely that the issue was with the Draytek or its setup (in particular QoS). However, after weeks of messing about and even trying a new router (Ubiquiti), the issue is very clearly Virgin in one way or another. I know this because if I test at my end on the Virgin connection, my phones suffer the same issue. But connected to the same Draytek router but on ADSL, there are no issues. I hope this all makes sense.

So, given that we have been able to determine the issue lies with Virgin, is anyone aware of any fundamental issues, either with the Virgin service or the Hitron router, that might be causing this? My guess is that it's the Hitron that's the issue, even in modem mode, but can't be sure of that.

In summary:

Virgin (modem mode) > Draytek WAN2 > VOIP = call quality issues
Draytek (ADSL) > VOIP = no issues

Thanks in advance.

Re: Any fundamental issues that cause VOIP issues?
 

Cable is an inherently jittery connection type due to it's broadcast nature and jitter is an anathema of VOIP. It does tend to mean call quality can be particularly pants on congested segments.

I also remember seeing some mention of static IP's causing problems with VMB connections due to how the connection is tunnelled, but dont know too much about that side of VM.

Re: Any fundamental issues that cause VOIP issues?
 

Thank you! So would this cause the issue I described? One call is fine, but as soon as another comes in (before it's even been answered!) the call starts to break up.

Re: Any fundamental issues that cause VOIP issues?
 

Yep.

Re: Any fundamental issues that cause VOIP issues?
 

I don't know much about jitter but I have exactly the same setup.

Hitron (modem mode) connected to Draytek router and Horizon Unlimited VOIP service (Polycomm phones). We are on the 200mb business package with a dynamic IP that has only changed twice in 2 years. 5 VOIP phones connected but I doubt there has ever been more than 2 concurrent calls, no users have reported any problems.

Perhaps congestion related as Skie points out.