Hello.

we have several customers who are all running SnomONE PBX.
they have a mixture of different SIP providers and different ADSL suppliers.
they are all running VIgor 2820's.

on a regular basis the SnomONE will loose SIP registration with a 408 time out error.
The only work around is to set up the SnomeONE as a DMZ and then remove it again.
this sort of prompts the 2820 to allow the registration.

any ideas as to why ?

Hi i found this on another website and it solved my issues

Symptoms: Registrations from SIP handsets behind 2820 routers in NAT mode randomly becoming unavailable and refuse to re-register. This exhibits itself on the SNOM 300 handsets that we predominantly use with the dreaded 'Network Failure' message.

Solution:

i) Check the firmware version on your router. 3.3.4.1_232201 (the lastest at the time of writing) seems to have some serious issues with SIP handsets. I have reverted back to 3.3.3_232201 which seems stable so far (fingers crossed)

ii) Make sure 'Accept large incoming fragmented UDP or ICMP packets' is disabled. This can be done in the web interface under: Firewall=>General Setup by unticking the checkbox

iii) Disable SIP_ALG. You'll have to telnet into your router to do this. Once logged in you will have to issue the commands:

1. > sys sip_alg 0 -- Disables sip alg

2. > sys commit -- Apply changes

3. > sys reboot -- Reboot router

Cheers for info
will revert one of the routers back to 3.3.4 and see how it gets on.

Cheers
Cid.

Have you tried the latest software 3.3.5.2 as it is surpose to solve most of the problems of earlier versions?
I know that 3.3.4.1 was totally useless for me but I've had no issues with 3.3.5.2 yet!

I will try and see what happens.