Solved Problems with non-standard SIP port

[Alex Rymshin]

I have PBX with SIP registrar running on 5060/UDP for the local users and non-standard port (say for example 6060) for remote. I have a problem with Windows 3CX client in the following scenario:

I make i call from any local extension to the remote 3CX Client:
host1.ip:6060 -> Invite -> host2.ip:5060
the client reply:
host1.ip:6060 <- Ringing <- host2.ip:5060
answer the call:
host1.ip:6060 <- OK <- host2.ip:5060
host1.ip:6060 -> ACK -> host2.ip:5060
now we a talking. All OK. And when 3cx client hang on, i can see:
host1.ip:5060 <- BYE <- host2.ip:5060
The problem is that the 3CX Client sends a BYE request to the port 5060 instead of 6060. So the host1 is still on the line.

Is it any possibility to fix this problem ? I use the option I am in the office - local IP anyway, but as i understand it doent matter ni my case.

 

[YiannisH_3CX]

Hello @Alex Rymshin

Do you mean you have changed the tunnel port of the PBX? After the port has changed you need to restart the services of the PBX and send a new welcome email to the 3CX clients that reflect the change. You can open a welcome email to make sure the port is correctly changed.
Also make sure that the clients have the option to use the tunnel located under the extension settings / 3CX client.
Make sure the new port is correctly forwarded to your firewall and that the firewall checker passes successfully.

 

[Alex Rymshin]

Sorry, but i don't know what is tunnel port of the PBX. If you are talking about "3cx tunnel something technology" then the PBX has nothing with 3cx. This is completely different vendor. I use only SIP & RTP ports for communications between PBX and clients. The problem applies to the 3CX Client only. There is no problems with other remote VoIP hardware/software.

 

[leejor]

So you changed the local SIP port on the 3CX client to 6060. What does a registration, from the client look like in the 3CX Activity Log? Does it show 6060, or 5060?

 

[Alex Rymshin]

No! I don't change local SIP port on the 3CX Client. I don't even know which port it binded to by default. (5060 as i see by logs) I just try register on the non standard port, 6060 in my case. There is no pioblems with registration or one way audio.It's all OK! I can call, i can receive call. But i can't correctly say BYE, because the BYE packets sends to the wrong port. Let see it at the picture - i made the following test stand:
Ext440 (local hardware phone/62.84.105.163:35060) make a call to the ext602 (Remote 3CX Client/192.168.2.23:5060). Ext602 answer from local port 5060 to the remote port 35060 (i changed it a bit), then send OK and then talking with Ext440 (RTP/10180 but it doesn't matter). But the last bye it sends from local port 5060, to the remote port 5060. Why ?

 

[leejor]

So you changed the local port at the 3CX PBX end, or, you are trying to use two ports 5060 for local, and 6060 for remote extensions? Are you accomplishing this by doing some port forwarding in your router? How does 3CX know that port 6060 is being used?

You're doing all of this why? In the hopes of avoiding hack attempts? In the past others have changed port 5060 to something else in the hope that hackers won't find the PBX, they still do. While that may be a number of scanning programmes that only search for port 5060, there are others that go after a wide range of ports.

 

[Alex Rymshin]

I don't use 3CX PBX! I use different vendor PBX. I just trying to use 3CX Client.
Yes! I use to different ports for remote and local registrations. The registration service binded to the local port. Remote registration mapped to the local registration port with the chains of routers and port forwardings.
3CXClient knows it (that i use different port) by using port notation in server registration string: for the previous example that was 62.84.105.163:35060
The question why this is done lies in the plane of technical possibilities and limitations. It is completely different matter question having little with the given.
I just want to ask "why 3CX client is not working correctly and how it can be fixed"?

 

[Vali_3CX]

Alex, what's the version of your 3CXPhone client?

 

[Alex Rymshin]

6.0.26523.0

 

[Vali_3CX]

Alex, that version has been discontinued about four years ago, we no longer provide tech support for it.

 

[Alex Rymshin]

May be i don't understand something, but i download it from the https://www.3cx.com/downloads/3CXPhone6.msi - Is it unsupported software ?

 

[Vali_3CX]

Yes, we kept the download link only, since that version proved quite popular and is still running on a wide range of Windows versions, but we no longer develop it since, as I said, about four years ago.

 

[Alex Rymshin]

OK. Thanks anyway!
I'll try to find some other SIP-client.