Recurring SIP Registration Loss on Snom M900 Multicell System

[Mehdi.Peyman]

Hello everyone,

At one of our customers, all DECT extensions lose their SIP registration simultaneously approximately every two to three weeks. The system only starts working again after restarting the M900 base stations.

• 3CX Hosted, V20 Update 9 (Build 987)
• Snom D865 used as a router phone/SBC
• 4 × Snom M900 multicell base stations, firmware version 790.200
• Snom M70 handsets
• Automatic provisioning via 3CX

During the outage, the D865 appears to remain connected to 3CX. Snom has already reviewed the configuration and diagnostic data but was unable to identify the cause. They recommended analysing the communication between 3CX, the D865, and the M900 base stations.

Has anyone experienced a similar issue? Which 3CX logs or diagnostic information should we collect and review during the next outage?

Thank you in advance!

 

[JohnS_3CX]

4 × Snom M900 multicell base stations

Ok so you are running in multicell mode, which has some special requirements. If the network requirements are not met, it's understandable that the outage will occur. Your discussion with Snom seems to point to network issues.

During the outage, the D865 appears to remain connected to 3CX

I assume you are using the D865 as a router phone, and have the M900 provisioned behind it.
Since the D865 remains connected, it's probably not the cause, however you can eliminate the D865 completely by adding a local SBC on the same LAN as the M900, and reprovision it to use this SBC instead of the router phone as its proxy.

Keep your SBC on a static IP (or DHCP reservation). This way, the next time the M900 acts up, you can at least connect to the SBC machine, run a packet capture, and see if the M900 is even making an attempt to reconnect. If not, then your M900 is probably facing some issues that only Snom can help with from there onwards.

 

[JohnS_3CX]

Oh and an extra note: Also ask snom about this setting here, because depending on your network one of those types may not work reliably in your environment.

 

[Claas Felix Beyersdorf]

You haven't told us how many extensions are on the DECT system.

Router phones are very limited about the amount of extension that can be registered via them.

So if we have multicell DECT we always use dedicated SBCs to ensure stable connections. But of course it depends on the amount of extensions you have on the DECT system.