asterisk users - Jun 2005 - snom 190: dial tone without registration?

Hello.

I'm currently evaluating the Sipura SPA-841, and snom 190 phones for use
in an Asterisk PBX/call center environment.

One feature the SPA-841 has, which I can't figure out how to implement
on the snom 190, is the "make/accept calls without registration"
feature. Or more specifically, "produce a dial tone even if I'm not
registered."

I would like to set our sip.conf entries to "host=<ipaddr>"
instead of
"host=dynamic" to enforce the IP addresses used by each sip phone. If
we
do this, Asterisk does not accept SIP registration from the phone on
that IP. This is fine with the SPA-841, but the snom 190 displays a
"NR"
status (Not Registered), and refuses to play a dial tone when you take
the phone off-hook. The phone will place calls correctly, but it insists
on thinking it's in an error condition when it can't register.

Note that Asterisk's "defaultip" option in sip.conf isn't
adequate,
because it doesn't deny access if the phone attempts to register from a
different IP.

Does anyone know how to do one of the following:
- tell the snom 190 not to register, but to use the outbound proxy for
  outgoing calls, and produce a dial tone anyway.
- tell Asterisk to enforce an IP address restriction for a specific SIP
  channel, but still accept an incoming registration from that IP.

Vitals:
- Asterisk 1.0.7
- snom 190 firmware 3.60i


Thanks,

Alan Ferrency
pair Networks, Inc.
alan@pair.com

On Monday 13 June 2005 16:42, alan wrote:
> Hello.
>
> I'm currently evaluating the Sipura SPA-841, and snom 190 phones for
use
> in an Asterisk PBX/call center environment.
How about tackling this with iptables and matching specific IP addresses on 
specific MAC addresses?

Cheers,
Gavin.

Gavin Hamill <gdh@laterooms.com> wrote:
> On Monday 13 June 2005 16:42, alan wrote:
>
> > I'm currently evaluating the Sipura SPA-841, and snom 190 phones
for use
> > in an Asterisk PBX/call center environment.
<snipped>
  enforce SIP channel IP restrictions in Asterisk without
  "host=<ipaddr>", or get the snom 190 to stop complaining when
it's not
  registered
</snipped>
> How about tackling this with iptables and matching specific IP addresses on
> specific MAC addresses?
This solves part, but not all, of the problem.

This ensures that only authorized devices can connect to asterisk, and
that their IP addresses are also correct. But it doesn't force
each device to use only its assigned sip channel.

(That is: with dynamic IP registration, a valid IP/MAC could be
configured with another device's SIP registration information, and steal
calls which should be going to the other device.)

I suppose iptables in combination with sip secrets should be enough.

But realistically, I can already do what I want the way I want to do it,
with the SPA-841. I mostly need to decide: if this feature is lacking,
is it enough for me to prefer the Sipura over the snom?

Thanks again,

Alan Ferrency
pair Networks, Inc.
alan@pair.com