[Asterisk-Users] Snom clients deregistering

[Michael Crown]

Does the phone ocasionally prompt the user for a password? -Mike

> -----Original Message-----
> From: Richard Watson [mailto:richard at openia.com] 
> Sent: Monday, November 14, 2005 5:00 AM
> To: asterisk-users at lists.digium.com
> Subject: [Asterisk-Users] Snom clients deregistering
> 
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
> 
> Hi all,
> 
> I have a server currently running Asterisk 1.0.7 placed out 
> in the wild (i.e. not behind NAT).
> 
> I have groups of sip clients all behind various NAT firewalls 
> (mainly adsl routers).
> 
> Up to now I've mainly used Sipuras and not had any serious problems.
> Recently I've been experimenting with Snom phones and I have 
> encountered  problems where the Snoms register fine initially 
> but after a while (which could be anything from 2minutes to 
> 45 minutes) they lose their registration. Sample snom 
> configuration in sip.conf follows:
> 
> [888120]
> type=friend
> username=888120
> mailbox=888120
> canreinvite=no
> nat=yes
> secret=secret
> host=dynamic
> qualify=yes
> context=sipdemo
> subscribecontext=sipdemo
> 
> I've experimented with several different adsl routers and was 
> surprised at the difference this can make, however the 
> problem is still there to a greater or lesser extent.
> 
> I've also tried using a Stun server following recommendation here:
> 
> http://www.asteriskguru.com/tutorials/sip_nat_oneway_or_no_aud
> io_asterisk.html
> 
> Again this makes a difference, but doesn't entirely solve the 
> problem - there are still occasions where the Snom is 
> unreachable or unknown.
> 
> The implication seems to be that if asterisk does not send 
> keepalives often enough then the way through the nat is lost.
> 
> I've also tried lowering the expiry time of the asterisk 
> sessions (in increments down to 30 seconds) in the hope that 
> it would result in more activity and keep the firewall open, 
> but it didn't help.
> 
> Another strange factor is using the BLF on snoms - the 
> situation seems to be worse with those enabled, but that 
> might not be relevant.
> 
> So I guess I have a few questions:
> 
> 1) Has anyone had this happen before and what, if any, was 
> the solution?
> 
> 2) How do I increase the frequency with which asterisk sends 
> keepalives?
> 
> 3) Does SER handle this better - would placing this outside 
> the NAT help handle connections from inside?
> 
> 4) Do newer versions of asterisk handle this better?
> 
> 5) Any other suggestions?
> 
> TIA.
> 
> - --
> Richard Watson
> -----BEGIN PGP SIGNATURE-----
> Version: GnuPG v1.4.1 (GNU/Linux)
> Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org
> 
> iD8DBQFDeGAzP05lUVhVYk0RAkM1AKCepBdfTkLoqwNlnbMpH3CWGTWCcwCeOFlE
> jbKdXnKHNqG7951KlctSfek=
> =ttdo
> -----END PGP SIGNATURE-----
> 
>