Was working briefly, now not..

[Ashthos]

I have set up 3cx Ver 9 on a windows 2008 server. The server has an IP address of 192.168.1.2

The server is Natted through a Draytek router, ip 192.168.1.1 (internal)

Phones on the internal network will connect fine.

The same phones, on the external network never connect(*) always failing sip registration.

(*) Not entirely true, one did once, then we had to reboot the server and never again.

Running wireshark I can see that:
a) all the ports are redirected correctly
b) the requests from the external phones are getting through to the 3cx server.

The requests from internal phones get one 407 Proxy auth required sent to them, they reply with the same register request with proxy information and register correctly.

Requests from external phones get a 407 Proxy authentication required sent, and they reply with the same request again without the required proxy authentication code. This happens for each and every register request. The 3cx server resends the 407 and the phone responds again without the auth information.

Please remember that these are the same phones, same firmware etc etc. Just ones external to the network do not send the authentication information for the proxy.

Testing with the 3cx softphone from the external location works fine.

I've tested the 3cx server with both port redirection and by putting it in the dmz and it always has the same outcome. (I.e the softphone can connect, IP Phones cannot)

The phones are the Siemens C460IP phones (complete rubbish, but they are what we have to work with). They worked ok when using an external voip provider, but bringing it in house has caused a bag load of hassle.

Does anyone have any idea why the phones aren't responding to the 407 in the correct way ONLY when they are external to the lan?

Or

Is there any way I can turn off the proxy authentication within 3cx? Given that I don't want to have to replace a load of actual phones this is by far the most attractive option!

Cheers

 

[leejor]

First off, it might be an idea to post the 3CX logs showing a failed registration attempt from an external extension. You don't say if the external sets are at different locations or all at the same external location, or if they are behind a router.

Have you enabled STUN on the external sets?

 

[Ashthos]

Hi, Thanks for your reply.

If you are talking about the Server Status in 3cx, then there is no indication of any connection attempt. It is only when intercepting the traffic on the 3cx box with wireshark can I see that any of the requests are getting through. I have the log set to verbose (Debugging) in [Settings -> Advanced -> Advanced]

The external phones (and softphone) are also running behind a router. So we have the following:

Internal Lan                  |                            |  External Lan
Phones & 3cx Server < -- > Router < -- > Internet < -- > Router < -- > Phones

So two routers are involved, but I don't have any control over the external router, But I do know the phones work correctly as (as I said in my first post) whist using an external (asterisk based) provider they worked fine.

Stun is enabled for the external sets and set to stun.3cx.com. External are all based at the same location.

I'm guessing that the external voip provider we were using had the proxy auth turned off, so would like to do the same with 3cx to see if the phones work. Otherwise I'll have to look to reproduce the pbx with something like asterisk to see if they work with that.

Kind regards

 

[Ashthos]

[Update]

Installed a small free SIP server on the Windows 2008 box to see if the same issue was happening. It was.

So tried the oldest trick in the book, rebooted the external Siemens C450IP phone base, and hey presto, all working again.

I can't explain why it would stop sending the authentication packets correctly, but, as I said in one of my other posts, the Siemens C450IP phones really are rubbish...

Thankyou all for your help.

(Posted primarily so someone else in the future with the same problem may find a resolution).