Mitel 3000 Call Delay

[Apersons]

I have a customer with a Mitel 3000 system. Analog trunks coming from provider and 5 phones.

Customer is stating that, when calling their main office in a different city, they sometimes get up to a 3 second delay between responses. It happens on all lines but the problem is intermittent. They've had the issue occur with other calls between clients, but the most consistent source is when they call their main office.

I'm open to ideas on where the problem could lie. I've not done much testing yet. I know i can plug a test set into the provider demarc and check there. But past that, I'm not familiar enough with Mitel to be able to work on their stuff.

 

[jcarmichael1203]

So how are these offices connected to each other? Are the remote phones setup in teleworker mode? Are they connected via vpn?
Does the issue occur in reverse? If someone from the main office calls someone in the remote office, is the problem likely to present itself?


If you arent familiar with both networks then I would start getting familiar. This sounds like a latency and/or bandwidth issue. I would say it is most likely an issue with the remote office, although I cant say for sure without knowing how the offices are connected to each other. If you have QoS setup on your switches and/or routers it might be worth it to double check and make sure that is all correct. Mismatched QoS could present itself as a problem, under the right circumstances.

I suggest googling for a mitel 3300 voice quality trouble shooting guide. For the most part the troubleshooting is the same regardless of software version. This guide will give you a good start as to what to look for. If you have access to the pbx itself, you should be able to turn on a voice quality monitoring. That will atleast give you some solid info on the voice quality.


Try to nail down any patterns in regards to the intermitten aspect. If there are any patterns that should help in determining whats causing the issue (ie, always in the afternoon, always on fridays, etc.) If enough people are using streaming media (video and/or audio) this could impact the performance. Similarly if you have network backups running during the day that would could also cause a problem.

It also might be worth it to determine how the phone is getting the call path setup. for example, internal calls usually have a call path directly between the ip phone sets. In your situation any external call will have a path that goes through the pbx and out the analog trunks.

I would probably test the analog trunks first just to rule that out definitively before getting too deep into investigating the network.
Without more info, I dont really know what else to suggest without being afraid of sending you on a wild goose chase.

 

[Apersons]

The mitel 3000 is a digital system with analog trunks and digital phones. There is no IP anything associated with this system. The two offices are connected only through the provider trunks as you would with any digital system.

We are going to start with the carrier and go from there. Are there any settings inside the mitel itself that might help smooth out the signal or decrease the delay?

 

[jcarmichael1203]

I do apologize, I thought it was the Mitel 3300. Basically disregard everything I said as you already know. Unfortunately, I dont have any experience with the 3000. I guess ill have to slow down my reading.

You might be able to change the voice codec. This might help speed up the signal conversion between digital and analog.

Regardless, good luck with your trouble shooting

 

[sarond]

I'm going to bet on a provider issue. They could have intermittent issues within their network.

Not sure how feasible it is but could you wire out sockets that are paralleled to the trunks and have them connect an analogue phone when the problem happens and use it to determine if it is outside the phone system.