VoIP breaking up (internally and externally)

You need end-to-end QoS to ensure good quality calls.

You say "site to site VPN", being a VPN over the internet? If so, you can never expect to have a good constant quality.

How do you connect to your external phone company?

Have you captured any RTP traffic to determine exactly where is the culprit ? Which end is the cause ?

So we are using DSCP 46 on switches, have dedicated bandwidth assigned to voice and qos enabled on routers.

We using SIP trunks from head office to connect to gamma.

Not captured anything as yet.

Here is what you can do based on my experience.

Shoretel is a cloud base phone system. You dont need VPN connection to establish connection the the endpoints unless you have some type of unknown configuration that I never dealt with.

The fact you have VPN shouldn't affect the quality of the voice. Since you're a professional IT like we are, I can think you have your network under control, meaning don't letting user do what they want in your network.

Now, here is some tips you need to consider. Check your network such as: (Bandwidth, application, network speed, and where the congestion lies in your network.)

If everything is OK in your network, call shoretel and find out what is going on. Remember the VoIP quality does not only depends on your bandwidth but as well the server. If shoretel server is congested you my friend will feel the impact of it.

Once more thing, shoretel depends on a trunk carrier, sometimes trunks are so congested that would be imposible to make a call without having any type of choppiness. I seen it before with VoIP.ms and some other carriers.

We have on premise solution not cloud PBX.

Oh, OK. Have you tried checking your carrier trunking?

Do this, Isolate the issue:

First: Call to any extension and speak with your colleague for 10 or 5 minutes. Doing so you will test your network bandwidth to determine whether your problem is internal or not.

If the first option successfully worked meaning no issue whatsoever, the go to the step two below

Second: Test your carrier trunking, help desk might tell you there is not issue but they're not the back-end. Therefore you will need to escalate the issue with higher desk. I had many issues like this, most of them because the carrier.

Let me know how it goes thus I can give you more guidance.
Cheers,

Yes, calls from HQ (where the trunks terminate) are fine.

Bandwidth isn't a problem at either site.

Tell me this:

How many phones you have in total? meaning in all the locations.

What's the bandwidth on each location? I think you told me the HQ has E1 2.48 mbps. what about the site is having most of the issue, how fat is it? is it oversea?

Does the problem happen when you call from another carrier to your phone system or from extension to extension.

Cheers,

35

100/100mb leased line at both sites.  Uk only.

However HQ is with ISP1, Site 2 is with ISP2.

What are you mean by "HQ is with ISP1, Site 2 is with ISP2." Like, you are using different ISP on each location? if that is the case that shouldn't matter.

35 phones is not even that much, in fact you shouldn't have any issue with choppiness and whatnot.
Having a symmetric leased line connection should be more than enough to handle any of your request.

1- have you tried rebooting your E1 modem? in case you are not using a modem and instead a PRI card did you try rebooting the router?
2- What type of routers do you have, also can you check the latency between ISP end.

The location you are having the mayor issue, what type of encryption are you using in your VPN?

I have to ask you these question in order for me give you an straight answer.

I repeat my original question:

Are you talking about internet connections when you say ISP? Are you two sites connected over the internet using a VPN?

Are your calls from site2 routed over that internet VPN to HQ site?

Please confirm or else provide a more clear description of the WAN technology to interconnect the sites.

@hemil

We have 100mb links from two differnet ISPs and routing over IPSec VPN.

No we have not restarted the shoretel equipment or router(s) as yet.  Running Cisco 5512X in a MPLS core and two cisco routers on premise (887va and 1921) for Site A.  Site B (HQ) no MPLS, just internet link from on premise firewall cisco asa 5505 and juniper SRX router.

Im unsure of the encryption used.  Will find out.  3des possibly...

@robocat:

Yes, internet VPN (however remote problem site is MPLS)

Yes

Thnaks

Yes.  
Remote Site - PC/Phones - LAN - Router - Cisco5512 (MPLS Core) - internet - VPN ---to--- VPN - internet - router - firewall - Head Office - PC/Phones.  So only different is the firewall location i guess.

I understand, however prior to moving remote site onto MPLS they had IPsec VPN and all was well - same ISP...

You can't do real QoS on a internet VPN.  Bandwidth management and some prioritisation at best, but not all VPN routers support this.

But the internet is unreliable, and not a good medium for standard VOIP. Especially as 2 different internet providers are involved who may or may not have a peering agreement. If the internet path has high latency/jitter/packet loss, you can never compensate for that with fake QoS.

@Robocat

You are correct, but in some scenario works. I had ran into a similar issue and I decided to configure my ASA 5505 with QOS over VPN and it worked like a charm.

Keep in mind I'm not saying is a solution, but is something he can try. I totally understand that ISP can disregard DCSP in their network. This is the reason why I told him to contact his ISP.

Please change your codec settings to G729

closing because no more comments from author.