Call delays inbound and outbound - Watchguard related?

[navarac]

Hello, I have a client that connects back to the 3CX server in my data center - i.e. there is no onsite server. When they receive calls, the 3CX client on their PC desktop rings immediately but the phone on the desk will ring only after the desktop client has rung about 3 times - about 10-15 seconds. When they place a call outbound there is a 10-15 second delay before the call goes through. I have set up an extension on their system at my office and the calls work correctly - no delays in or out. This client recently got a new Watchguard router and the problems/delays seem to have started when the router went in. Does anyone know what could cause these delays?
Thanks.

 

[navarac]

I tried an experiment and had the phones connect directly without autoprovisioning and there was no delay. I tried it with autoprovisioning the default template and the delay returned. Anyone have any idea what might be in the template that is causing the delays? I should have mentioned that the phones are Yealink T23G.

 

[YiannisH_3CX]

Hello @navarac

You mentioned that the phone in your office works correctly, i assume with auto provisioning but the phones in the clients office have a delay with auto provisioning. Is that correct?
If so how are the phones provisioned? Are you using an SBC or STUN?