Lag when forwarding calls to a cell phone(Spectrum)

[Twotone]

I have 3 phone systems setup with 3CX. The 2 clients that have Spectrum get horrible lag when forwarding to a cell phone. They use the Grandstream 2170s with the Grandstream GXW-4104 as a gateway. Spectrum uses their own digital boxes to convert their phone lines to analog so we're thinking that the fact that it is going from digital to analog to digital is causing the issue. Their phone calls will sometimes just drop as well occasionally but not too often. I'd rather work on one problem at a time though. The lag to the cell phone and the fact that you can sometimes hardly understand the person being forwarded is the main issue at the moment. Any help would be appreciated.

 

[leejor]

The only thing you will be able to confirm, and rectify if needed, is that 3CX (or something else that you have control over) is not causing the call to be delayed. It may very well be a setting in their ATA that is causing some some of the delay, but, as you say this is happening only with calls to a cell phone (all providers?), I have to assume that how Spectrum is handling the call, is the primary cause of the delay.

I would bring this up with them. They may have an issue, with a route, or routing tables, for certain types of calls, that they may not even be aware of.

 

[Twotone]

The only thing you will be able to confirm, and rectify if needed, is that 3CX (or something else that you have control over) is not causing the call to be delayed. It may very well be a setting in their ATA that is causing some some of the delay, but, as you say this is happening only with calls to a cell phone (all providers?), I have to assume that how Spectrum is handling the call, is the primary cause of the delay.

I would bring this up with them. They may have an issue, with a route, or routing tables, for certain types of calls, that they may not even be aware of.

I have talked to Spectrum's support and of course they immediately point their fingers at something I have setup and won't even look at their system. I may try to call them again. Yes it is with all cell phone providers.The question is 3CX and Grandstream related is where would I start to verify that it isn't one of them causing the problem. I would think it would be the Grandstream gateway over 3CX because it is handling both calls simultaneously. Do you think Grandstream support could take a look at the setup on that gateway to see if it is an issue with it?

 

[leejor]

Have you first confirmed that 3CX is passing on the call, to the gateway, without delay (3CX Activity Log)? (no time difference between a land line call and a cell phone call) Next, get yourself an analogue phone, and place some test calls direct from their device, at your site. Test each line to see if you encounter a delay for each type of call.. It may not be as long as what you experience when calling on a 3CX extension, but you should be able to prove where the delay is occurring by eliminating your portion. It could very well be a setting in their local device.