Delayed Incoming and Outgoing calls

[comp4all]

Hi,

I'm having an issue with one of my customers.
Their incoming and outgoing calls are delayed between 5-10 seconds.
from time to time the phone(Remote Stun) is registered but no incoming calls and it takes quite a few goo restarts to recover.
They have the following configuration:
The building provides internet to the office so we are on their Router and we are connected with a router of our own.
We have configured NAT so the router will work.

Any idea why we get delayed and from time to time we cannot get incoming calls?

TIA

 

[JohnS_3CX]

Are you referring to the SBC? Yes it would be a machine that is on the same network as the phones.

The phones talk to the SBC, and the SBC talks to 3CX

 

[AWS2P]

just look at this
https://www.3cx.com/docs/manual/firewall-router-configuration/
https://www.3cx.com/docs/3cx-tunnel-session-border-controller/

 

[comp4all]

Thank you, John.
now I don't have to wait 5-10 seconds before the phone rings.
I'll do more tests tomorrow.

 

[JohnS_3CX]

No problem, please remember to do the following once the SBC appears connected in the SIP Trunks section:

1. Remove assigned phone from the extension
2. Reset the phones (they might ask user/pass due to previously being STUN, but ignore that)
3. Go in the phones tab and find them in bold
4. Select phone and assign to extension (it should fill in SBC settings automatically in extension's provisioning tab)
5. Remove PBX Delivers audio from the extension's Options, it's not needed now
6. Press OK to save
7. The phone should provision and come online shortly
8. Dial * 777 for Echo Test and ensure you have audio