M900 Snom Cause: 404 Not Found/INVITE from

[Biid00x]

Hello!
I have 2 SNOM DECT base connected in multicell with the latest firmware.
Everything was working for few months, however since today one DECT base is not working.
All the extensions connected on the one not working can call outside. But they can't receive call from outside or even inside .
My 3CX is in STUN and self hosted.

Now, inbound calls are immediately dropped with the following error...

19/05/2022 15:48:06 - Call to T:Extn:105@[Dev:sip:105@*********************:5075;line=61257] from L:2558.1[Line:10000<<+*********************] failed, cause: Cause: 404 Not Found/INVITE from *********************:5075

19/05/2022 15:48:06 - [CM503003]: Call(C:2558): Call to <sip:105@*********************:0> has failed; Cause: 404 Not Found/INVITE from ***************:5075



Ext 105 is well registered. I can see it connected on 3cx homepage.

I've changed the default port for the DECT base: it's not the 5060 but 5075.
The RTP ports are 14200-14219

Have I missed something fundamental in the settings for this device? Any advice welcome!

Regards,

 

[Saqqara]

Did the issue start, after you changed the sip port from 5060 to 5075

 

[Biid00x]

No, the problem appeared this morning. But the configuration didn't change since the installation.

 

[JohnS_3CX]

Is it working in STUN mode?

 

[Biid00x]

Yes it is working in STUN mode. Is that a problem?

 

[JohnS_3CX]

Hi @Biid00x


The problem with STUN, is that it might work fine for a while, until one day it stops with no reason given...
I suggest to install an SBC to make it more reliable
Just to be clear: It does not matter whether it worked fine before or not, this is a requirement when using STUN.


Firmware considerations:
Now that being said, you should also read Snom's instructions carefully because there are specific notes on each firmware version that will affect the performance of the device. You can upgrade sequentially to each version, until you reach the latest making sure to read their release notes, especially regarding repeaters.
https://service.snom.com/display/wiki/DECT+M-Series+Firmware


Note: we do not provide support for multicell (so you might need to reach out to Snom), but if you setup the main base and it works fine, the multicell can then also be added and I expect it should also be fine. 3CX will only see the main device, and that device will communicate with the repeaters fine so long as they are all connected on the same LAN.

 

[Biid00x]

Thank you for this answer!
Just a question concerning the Ports Used by 3CX Phone System. The ports need to be open in incoming traffic?
Or if the firewall is fully opened in outgoing traffic is that okay?

 

[JohnS_3CX]

Hi,

Outgoing traffic:
Allow all

Incoming traffic:
Port forward it on both sides
- the phones need their own specific ports forwarded as per the article I shared earlier
- and the PBX needs all the ports described here and have a "YES" in the Required column https://www.3cx.com/docs/ports/


Alternatively, if you install a 3CX SBC, you do not need to port forward anything at the phones site. This is considered a superior solution that bypasses NAT restrictions and does not require you to open ports. Let me know if you need more information!

Just to confirm though: where are the phones and where is the PBX hosted?