Snom D785 3cx V18 missing keepalive

[mreinder]

This weekend I updated our company 3cx server from v16 to v18. Everything looks right but on monday the problems started. The snom phones on outside locations (connected trought vpn) are losing registration. The screen says "Not registered" After some debugging I found the below. For now I changed the sip session timer to 60seconds and the problem looks gone but there should be something wrong. I'm running on the latest firmware 3cx provides snomD785-SIP 10.1.84.15 .

Feb 1 08:04:31.792 [DEBUG1] SIP: Missing Keepalive (STUN) from (Udp:10.1.1.16:5060:ȇ :3791140)
Feb 1 08:04:31.792 [DEBUG0] SIP: sip::closed_reg_connection: reg=0
Feb 1 08:04:31.793 [DEBUG2] GUI: If_Registration(REFUSED, 0, [email protected]:5060,)
Feb 1 08:04:31.793 [DEBUG2] CSTA: Received LocalIdentityChanged for identity [email protected]:5060
Feb 1 08:04:31.794 [DEBUG2] CSTA: Reporting event 'OutOfService' to monitor 1
Feb 1 08:04:31.795 [DEBUG2] CSTA: Received LocalIdentityChanged for identity [email protected]:5060
Feb 1 08:04:31.795 [DEBUG1] SIP: Identity 75akxl6n connection id Udp:10.1.1.16:5060 clear
Feb 1 08:04:31.795 [INFO ] SIP: stop subscription 0/31363433363938393533373731-btxa9eqzxlvv
Feb 1 08:04:31.795 [INFO ] SIP: Identity 1 reregister in 30000 ms.
Feb 1 08:04:31.795 [DEBUG2] SIP: Sending uaCSTA event on sip connection 1.
Feb 1 08:04:31.796 [DEBUG1] SIP: Routing to outbound proxy: sip:10.1.1.16:5060
Feb 1 08:04:31.797 [DEBUG1] SIP: RoutePendingPacket 1004924: entry=url ? sip:10.1.1.16:5060 all 2
Feb 1 08:04:31.797 [DEBUG1] SIP: RoutePendingPacket 1004924: entry=Udp:10.1.1.16:5060 all 2
Feb 1 08:04:31.797 [DEBUG0] SIP: Use Connection Udp:10.1.1.16:5060 for packet 1004924
Feb 1 08:04:31.797 [DEBUG0] SIP: send INFO (706: _64Ghw01Vbm-ri1tORWEuQ..) -> Udp:10.1.1.16:5060

 

[JohnS_3CX]

Hello,

If you deployed the phones using a VPN, then you need to set up the phone in 3CX as LAN.


However, it is your responsibility to ensure that the VPN is transparent, such that the phone thinks that it is on the same LAN as your PBX machine. This means you should not filter out any LAN traffic, and that includes STUN requests.

We have explicitly added 60 second keep alives for LAN and STUN provisioning to keep the phones more stable.
We assume that you will not be using custom templates, and that you are running the latest V18.

Please try to factory reset and reprovision the phone from scratch (without any custom templates) and then monitor your phone for a couple of minutes.

Example of a D785 keeping the connection alive with the PBX on a LAN environment

 

[mreinder]

Thank you for your fast reply. The vpn is not initiated on the phone but between the modems of the different locations. Nothing is changed in that part. The only change is the upgrade to 3cx v18. And indeed the extentsion is setup as local lan.

Sorry forget to mention, the phone is reset to factory and we use the default templates, but the problem still occurs.

 

[JohnS_3CX]

I think you need to inspect the traffic to see what happens.

If I had to take guess, it will probably the the VPN filtering out STUN requests, meaning that the requests sent by the phone IP will not be receiving the reply from whatever the PBX IP is (like my screenshot above).

 

[Ebiscuit]

Hi,
faced a similar or same problem...
When using the the Snom Phones and 3CX Provisioning - even when you choose Local Lan - this will set
Keepalive-Intervall (s) 60 for the NAT settings of that identity.

keepalive_interval1=60
without any additional STUN Server settings configured.
This forces this side effect here in my home installation and at a customer site
to show this short "reregister" issues on the phones.
and showing STUN request to the 3CX IP (also visible in the phone log)

Removing that setting in the template (or the phone and disabling the provisioning) will stop that behavior

 

[mreinder]

Thank you, for now I changed a template to register every 60sec instead of 120 sec in de default template, but wil test your option also.

Yes that seems to work.