SPA942 config

[Secint]

Hello,

I know this phone is no longer supported by 3CX, but it should be possible to configure a SPA942 with a 3CX phone system. The phone registers, but i cannot receive incoming calls. I won't ring. I can make outgoing calls. Anyone any idea?

I forwarded ports 5060-5080 for UDP and TCP to the adress of the phone, i also did that with ports 16384-16482 for UDP/TCP (intended for RTP, but i can only chose (TCP/UDP/both) in my router.

 

[leejor]

It sounds as if the set is remotely located. Is there just the one set at that location?
Are you using more than one line key on the set?
Has STUN been enabled on the phone?
What does the sets registration attempt look like in the 3Cx Activity Log? Do you see the public IP (of the remote router) and port, or is it showing a private IP and port?

 

[Secint]

Hello Leejor, thanks for your reply. The phone registers perfectly, it's just that incoming calls aren't working. The phone doesnt even ring. I can make perfect outbound calls though. Stun is enabled via stun.3cx.com. Stun test is disabled though.

 

[leejor]

If it is just a single device (single IP) at that location , then usually, no forwarding on the local router is required. If you have other SIP devices, or have used a device (android or iOS App) that shares the SIP port (usually 5060 and up), there might be an issue.

If the 3CX registration look correct, then that is where a call to the extension call will go. Check the Activity Log right after a failed attempt to see that the destination is correct and what the error actually is.

There may also be a setting on the router that requires changing, or perhaps a firewall issue.

 

[Secint]

The problem is that the 3CX is provided by a third party, and i cannot see their log files. If I use my cellphone to call the number it says 'the number you are trying to call is unavailable and might be switched off'. Is there a way to check the problem from the phone log?

 

[Secint]

one thing to add: I can receive AND make calls if i use Zoiper on my laptop with the same registering credentials, hence the problem must be within the phone for some reason

 

[Cjay]

NAT Keep Alive sometimes helps with problems like this (set it to yes)

 

[cobaltit]

@Cjay

Probably not in this case. NAT keep-alive is the solution where you can receive a call right after reboot/register/making a call but then can't a few minutes later. In those cases registration or outbound calling opens the ports for response traffic until the UDP time-out on the firewall. Keep-Alive keeps those ports open. The proper solution is to have port forwarding setup. The problem is more than likely that you are may be forwarding the wrong ports. For a 3CX Supported phone it usually wants you to forward something like 5060 and then 14000-14009 for the first phone and then 5061 and 14010-14019 for the second, etc. I would try simply forwarding 5060 to the phone for now. That would at least get the phone to ring. If no audio you can then start trying to figure out what RTP range to forward. It's tough since you don't have access to the 3CX instance because a wireshark would tell you what ports it's trying to use.

 

[leejor]

If you use another SIP program, on the same network (Zoiper), and it, and the line key you are trying to use on the SPA, happen to be assigned the same port, then some routers are going to remember the last device to use the port and try to send a call to them. Try resetting (power down and up) your router, then only trying the SPA. Make sure Zoiper is "offline".

 

[Secint]

Hello,

In het router I forwarded ports 5060-5080 and 13000-17000 to the IP adress of the phone, both TCP and UDP. Still no result, Zoiper is online and I restarted the router. Still no results, what am i missing?

 

[leejor]

If Zoiper is working at the same location, then it is either a router issue, the registration from the set is incorrect, or something on the set causing it ignore the Invite. You can check to see what the Invite looks like, on the local network by using Wireshark. I'm assuming that only key 1 , on the set is enabled. In the SPA status page, does it show as registered?