Re: [Newsip] NO PTSN access

[Ben Smithurst <ben.smithurst@gradwell.net>]

James Rossell - Centric IT Ltd wrote:

> Okie now its not working again.
>
> Getting an error tone and a person saying "The person you are calling
> is unavailable" and x-lite is showing a proxy authentication error.

This appears to be a problem caused by having multiple servers - I have
noticed similar intermittent failures on registration, but not when
making calls.

The problem is basically that the dialog goes something like

client sends INVITE to newsip and it goes to server1
server1 replies "need authentication"
client sends INVITE with auth to newsip and it goes to server2
server2 doesn't like the authentication data because the challenge was
	generated by server1

We will have to think of a good way of solving this, however I think in
the meantime you will have to adjust your DNS to only use one of the two
IPs (it doesn't matter which).

That will unfortunately mean you'll have to wait for the DNS to update
again... apologies for that.  May I recommend you set the TTL on your
newsip records to something quite low (perhaps 10 minutes) so that if
you need to change it again, caches will clear more quickly.

[ I have a feeling this problem may only show itself via the NAT proxy.
My snom phone on a public IP never has a problem, because I assume it is
clever enough to use the same IP for both requests, but the NAT proxy
doesn't have enough intelligence to do that.  We may have to talk to the
vendors of the nat proxy appliance to see if that is something that can
be resolved. ]

cheers
-ben

-- 
Ben Smithurst       ben.smithurst@gradwell.net                  Gradwell
Senior Developer                                http://www.gradwell.com/

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