Rain ISP and 3CX

[Moonstruck]

Good day

I would like to find out if anybody has configured a 3CX system on Rain ISP.

When I connect via Telkom ADSL everything works fine, but when I switch to Rain ISP. The phone rings and when I answer there is no sound and the phone calling says dailing but no dailing tone.

Thank you in advance for any solutions.

 

[StefanW]

as you switch the public IP, depending on how 3CX has been set up, you need to update some settings in
Settings --> Network to match your new public IP...

 

[leejor]

Was 3CX originally installed on Telkom, then changed over to Rain, or did you do a brand new install (from scratch), on Rain? Was the same router (with all of the required ports forwarded) used?
If you run the 3CX Firewall Checker...does it all pass?

The fact the phone rings, but no sound, would suggest a blocked port, or less likely, a Codec issue.

 

[Moonstruck]

3CX is installed on Gcloud with static IP.

Installation was done via Rain.

Phone is Yealink W52P and with auto provisioning.

I am using the FQDN and not the IP as the IP would not auto provision.

 

[Moonstruck]

Forgot to mention that on both ADSL and Rain the firewall check passes

 

[JohnS_3CX]

Hi @Moonstruck

So the PBX is in the Google cloud, and the phones are remotely installed behind a Rain access modem?

Do you use SBC / VPN / STUN to connect the phones?

What is different between the two ISPs other than the public IP? Are you using both connections in the office and have one link as the main and the other as a failover?

 

[Moonstruck]

@JohnS_3CX

Yes the phones are behind the Rain access modem.

I have setup the dect phone as per documentation and using the auto provisioning link.
Please see attached screenshot

Only difference is the ADSL is 4MB and The rain is LTE-A

I would like to use the Rain as my main and the ADSL as my failover. but at the moment I must use the ADSL so that the phones work.

 

[JohnS_3CX]

Ok please consider that the LTE connection may actually be the issue here, most often the provider will use shared IP addresses for LTE meaning that you might actually behind the ISP core network firewall / NAT sharing the same IP with other subscribers.

This means that the traffic might not be reachable from the PBX to the LTE connection at the office (unless you have a static IP with no NAT from the ISP). As a possible solution, you can use an SBC with encryption which will help your system better traverse through whatever NAT the ISP has.

You have not mentioned how the phones are connected, SBC / VPN / STUN ?

 

[Moonstruck]

@JohnS_3CX Thank you for this info.

It is STUN connection

 

[JohnS_3CX]

Ok, in this case you will likely benefit from the SBC since you won't have to worry about any ports being blocked via the LTE connection.

The tunnel on the SBC will pass the SIP messages and the audio to the PBX via the tunnel port. When the ADSL connection goes down and you switch to LTE, the SBC will re-establish its link with the PBX shortly and you can continue to use your phones.

 

[Moonstruck]

Thank you @JohnS_3CX I will give this a try.

 

[StefanW]

plz delete the screenshot as it contains vital information about your install

 

[Moonstruck]

plz delete the screenshot as it contains vital information about your install

I don't have that option please assist

 

[StefanW]

I have deleted the image on your behalf

 

[3C Technology]

Hi Moonstruck i believe that RAIN do not have an unrestricted APN witch is what you will need. Perhaps give them a call and ask them if they have an unrestricted APN.