Help with call quality issues.

[mrdon515]

We just had a phone vendor install a brand new Avaya Office Essential phone system into a new building of ours. There are nine 1408 phones and one 1416 phones.

We have a 4MB internet connection (up and down) that the phone system is using to route calls and for an internet/vpn connection to our main office.

Call quality for internal calls is fine, but for outside calls the customers on the other end hear a lot of clicking and say that our users voice cuts in and out.

We have a Sonicwall router that the phone system plugs into as well as the users pc's. We have setup route prioritization for the VOIP and given it guaranteed bandwidth, etc. Our ISP has even setup QOS for the VOIP traffic, but we are still experiencing poor call quality.

We have also adjusted the Sonicwall router according to the Avaya documentation here:

http://www.ipofficeinfo.com/docs/Ports

IP Office.pdf

Me being the IT manager, things have fallen to me to try and figure this out. I get the feeling that the phone vendor is at a loss and that maybe they haven't installed too many of these particular systems before. This is the first IP system I have ever dealt with.

Any help would be greatly appreciated.

 

[amriddle01]

With IP phones call quality issues are the network, simple as that. That's how the voice gets from A to B, that's where you need to look. Internal is fine means it's not the internal network/LAN so it must after that point, probably the fact it runs over the internet or does the service providor guarentee low latency and QoS as the calls transiits the net by keeping it within their equipment? It's easy to check, watch the call in progress in SSA, it will show jitter, packet loss etc as will the handsets, compare an internal call to one that transits the external link

http://www.ipoffice.tel

 

[mrdon515]

Thanks for the reply. I am guessing that the SSA is the phone systems management interface?

 

[amriddle01]

No, it's a monitoring tool that gets installes alongside, you can also get to it by web browsing to the system IP address, click on the System Status Application, when it has launched enter the same username and password you use to manage the system

http://www.ipoffice.tel

 

[Westi]

the tools for a network assessment are the ones that will show you if your voice is actually prioritized and what bandwidth you can achieve. SSA is giving you a hint of what might be wrong but can't pinpoint it.
You need to have 2 PC's running one on each side of your VPN and have them exchange packets on the voice VLAN tagged as voice packets to be able to tell if the connection is good enough for voice.
Seeing that you have digital phones on the one side there will never be internal issues as it doesn't use your LAN and only to the remote side it uses VoIP.

Joe W.

FHandw, ACSS

16184

 

[amriddle01]

Ha, you're right for some reason I thought they were 1600's. Just watch the external calls in SSA then and see how much jitter packet loss etc you get

http://www.ipoffice.tel

 

[mrdon515]

I just requested the login info from our vendor, so I should be able to check that out shortly.

Not sure if this is a somewhat reliable method, but I ran the VOIP test a few times at

http://myspeed.visualware.com/indexvoip.php

and it did report a fair amount of jitter, from 21ms to 31ms.

 

[piethief]

If it is behind a VPN, then the ISP can't really give you Qos on voip traffic. Think about it, it is encrypted, so they have no way of knowing it is Voip. That's the point of a VPN, security.