Solved Provisioning Issues, Yealink & SBC

[Kharon]

Hello,

I have been pulling my hair out for days trying to figure out what is going wrong with my system, Hopefully somebody can shed some light on what I am missing.

• 3CX Version, Standard Annual 16.0.8.9
• Server OS, . Windows Server 2019
• Is the 3CX Server Hosted and where? Private Colocated Server
• IP Phone Make/Model/Firmware / Yealink T23G 44.84.0.140 x 3 & Yealink T40G 76.84.0.95
• Provisioning Method: VPN and SBC
• Trunk Provider : Aatrox Communications
• Has the Firewall Checker passed: Yes
• Are custom Phone Templates being used: No

3CX server at 192.168.101.252
Site 1 at 192.168.1.1
Site 2 at 192.168.0.1
VPN address space at 192.168.124.1

We also have Android mobiles that connect direct to the 3CX server with the App and these work perfectly.

We have 2 remote sites, one has a single T23G and connected by VPN, This phone will only register on TCP and only voice only works 1 way, outgoing only, was previously working fine.

The other site has 2 x T23G's and 1 x T40G, this site has recently been relocated to another premises, previous site was working flawlessly through the VPN on UDP settings.

The Site 1 network consists of 4 x L2/L3 Managed Switches and an Untangle Firewall with a PPPoE internet connection, The only thing that has changed in the site relocation is the number of switches and the internet connection, It used to be a VDSL connection.

Site 2 connection is on VDSL

At the new site, only 1 phone would register on UDP and the others has to be either TCP or TLS to register through the VPN, however audio in was perfect, audio out was choppy.

I put this down to issues with OpenVPN since both remote sites are affected and is not possible to change to a different VPN at this time, so I tried an SBC at Site 1

I installed an SBC on a Windows Server 2019 on HyperV on the local server at site 1, however I was having issues with the SBC and VPN being on the same IP range, the phones were getting confused. I changed the SBC and the phones to IP 192.168.10.1 range with Vlan ID as 10. This is not exposed to the VPN so is forced to exit through the internet connection.

The SBC is connected to the 3CX server without issues. All the phones can ping the SBC. 1 of the T23G's connected to the SBC via UDP without issue and was working perfectly, It fixed the audio issues. While trying to get the other 2 phones to connect to the SBC the first phone disconnected and now none of the phones will connect to the SBC, They just keep failing to register regardless of using UDP, TCP or TLS.

I have tried factory resetting the phones, changing ip addresses, using static or dhcp, nothing I try seems to work.

Please let me know if further information is required.

If somebody could help me with this it would be greatly appreciated.

Regards,

Trent

 

[JohnS_3CX]

Hi Trent,

It sounds like most of your troubles are down to networking, and I can understand that can be a pain to troubleshoot.

When it comes to VPN though, we cannot provide any assistance. The best we can advise is:

- Do not install the VPN on 3CX if you must use one, keep it on another machine or router
- Make it transparent to the phones, such that the phone thinks its on the same LAN as the PBX
- Or don't use a VPN at all if the above cannot be met - you will run into issues like above

Suggestion:
Given that you have issues here, it's safe to assume that the VPN has not been implemented in the above manner.
You were on the right track with SBC though, but perhaps something was left behind, so give it another shot with a clean slate:

Setup an SBC on the network segment where you will put the phones, and ensure that it can reach the internet and that it allows multicast. No VPNs live here, just your phones and SBC machine with a clear path to the internet.

Make sure that no funny business is happening on the managed switches, remember the issues you are facing are quite likely due to network setup, and our goal is to simplify this part now.

Now the fun part: delete the phones from their existing extensions to free them up, then factory reset them.
If all went well, they should appear in bold in the Phones section. Select them one by one, and click "Add Ext" to add them to a brand new extension, one that you will leave untouched - do not change any of the settings!
Hopefully, the phone will become registered and should work both ways with full audio.





PS: The SBC machine should have absolutely nothing else on it other than the OS and the SBC.
You can also run on Debian using our ISO, without having Windows hogging valuable resources.

 

[Kharon]

Hello,

The VPN is between 3 Untangle Firewalls, completely independent and altho they are in different IP ranges, everything can talk to each other and as stated this setup worked previously before moving premises which is the most confusing part.

I will try your suggestion, reset everything and reinstall the SBC. I will let you know once I have done that.

Regards,

Trent

 

[JohnS_3CX]

Sure thing, let us know and we can take it from there!

 

[Kharon]

Hello,

After factory resetting all phones and reinstalling the SBC, everything is working perfectly including the remote phone through the VPN. I have no idea what was wrong but is is all good now.

Thanks for your help.

Regards,

Trent

 

[JohnS_3CX]

Great news Trent, glad to help!