Delay before connecting extension Between harware IP Phone and 3CX

[groupe10]

Hello,

I have my 3CX V16.0.9 instance installed on a VM (Microsoft Azure). We have 5 IP Phone (Grandstream GXP1628) connected into the lan of our office and 3 IP Phone (GrandStream GXP1625) installed in different houses of our staff and some Softphone on iOS devices.

Every external incoming call connect to IVR within a second. When they dialed extension, it makes the IP Phone and the softphone ringing within a second too, but when we answer at IP Phone, it could take 8 to 10 second to have audio. We do not have that delay if we answer with a softphone located in the same lan of the IP Phone (Via Wifi).

For outbound call, we have the same issue. We are dialing the external phone number (Or another extension of our 3CX) and it could take 8 to 10 second before having audio. When the audio connect after that delay, we do not have any other delay until we hang up. If we are using the softphone (located in the same lan of our IP Phone) to make an outbound call i do not have the delay. But if the softphone dial another IP Phone extension, we have the same delay.

We clearly have an issue between 3CX and hardwire IP Phone instead they are located in the office or other LAN (or co-workers house). This is not an issue between 3CX and VoIP Provider or between 3CX and Softphone.

What can i do to fix that problem ?

 

[NickD_3CX]

Hi!

I am assuming that the 8 IP Phones (5 at office and 3 at staff houses) are setup as Remote STUN/Direct SIP, as you don't mention anything about an SBC.

First things first, have you done the necessary configuration on the Remote Location Routers/Firewalls (in your office and at houses)?

On a more technical level, this delay I suspect is because the IP Phones aren't receiving answers to the STUN requests they are sending to the 3CX Server, and the delay effectively is the 'timeout'. If this is the case, you are lucky you are even getting audio.