Solved Yealink T23G No Service via Azure

[Wilko]

Hi all,
We have divided to move from our in house 3CX NUC to 3CX on Azure. The Azure setup has been straight forward. Moved our current config over and fired straight up. On Windows 3CX and on Android 3CX it works just fine however our Yealink T23G are provisioning but are stating 'No Service'.

I've gone through everything including all other posts to no avail. If we drill in to the warning on the phone it tells us that the Account is Unregistered. I'm assuming it is a SIP problem but can find what it is thou i'm sure it will be something silly in the end.

Any suggestions?

Ben

 

[JohnS_3CX]

Hi Ben,

Since the PBX is hosted in the cloud, the phone will need a way to reach it and usually your firewall will get in the way of things. This is achieved via STUN provisioning (the hard way if you have more than couple of phones) or by using a 3CX SBC (the easy way when it comes to provisioning, security, and compatibility).

Windows and Android work fine because they have a tunnel built-into them, the SBC does something similar for desk phones.

https://www.3cx.com/docs/3cx-tunnel-session-border-controller/

 

[Wilko]

Thanks for the speedy response John, I had configured it to use STUN provisioning. The Yealink found the config file and changed all the setting in the phone but it still came up with No Service. I checked the ports on both ends and tried many options i read on the forum to no avail. I understand an SBC is great for an office environment but were looking to employ individuals working in a home base environment and really don't want to add a SBC to each employees phone. A simple plug into the internet would be the best option. Any further suggestions?

 

[Saqqara]

Couple of things to check.

1, Blacklist - check to see if the IP address has been blacklisted.
2. 'Disallow use of extension outside the LAN (Remote extensions using Direct SIP or STUN will be blocked)' is unticked, under Options for the extension.

 

[Wilko]

Saqqara, Thanks for you response. I found forums on both those and neither of them corrected my problem.

 

[JohnS_3CX]

Hi Ben,

A good starting point is what @Saqqara said, but you still need to open the SIP and RTP ports on that user's modem as well as disable ALG when the device is finally deployed. You should not expect consistent results without this.

We would not consider STUN phones to be a simple plug into the internet deal, since they rely on having their ports forwarded correctly. For that only the 3CX clients are reliable (since they have a tunnel). So in your case where no SBC will be configured, you will need to do the following instead:

1. Setup the phone in the management console to use STUN (with its own unique SIP+RTP ports)
2. Ensure STUN is not disallowed on the extension
3. Factory reset the phone - mandatory since you are troubleshooting now
4. It will ask for user/pass when it successfully reaches your PBX for provisioning
5. Ensure the firewall is correctly configured to forward that specific SIP+RTP port combo on the phone's local IP
6. Also ensure the firewall checker passes on the PBX side

If the above is all done and you still can't register, then it's time to run a capture on your firewall, filtering for your phone's local IP.

 

[Wilko]

John, Thanks for the support.

Just so i can ensure that we have the correct ports open, is it just the SIP+RTP ports we need to open and direct to the IP of the Yealink phone or are there also others? I could't find a lot of information yesterday for setting up ports at the hand Set end when using STUN.

Regards
Ben

 

[cobaltit]

https://www.3cx.com/docs/manual/configuring-ip-phones/#h.ul2fzupi6t22/

The very bottom section is what you are looking for.

 

[Wilko]

Thanks all for your guidance.

So today i got the craps on and built a test system on GCP.. Worked and sync'ed straight out of the box.. Moved my system and now have all 3 Yealink phones online, tested and all appears to be as it should. Tomorrow morning will be the test but am very confident... done a bit of testing.

As for Azure.... Look i'm lost. I would of liked to stay with them as we have O365. I chatted with one of their tech's online and came up with nothing. Their firewall seams to have a hurdle i could find. I'm taking the easy path which is the one that works out of the box..

Thanks again all.

Ben

 

[JohnS_3CX]

Hi Ben,

I'm glad it was resolved in the end. For future reference, the system provides a method to capture traffic on the NIC of the machine, this can help to see if the traffic from the phone reached the machine (for troubleshooting the firewall).

Equally, you can also run a capture on the phones site firewall, and see if the phone attempts to contact the PBX and whether the local firewall allows it to send its traffic.