> On Mon, 2009-04-06 at 15:40 -0400, Paul Mossman wrote:
>
> > > Just to make sure: the SRV 1/2 thing is a joke right?
>
> Yes.
>
> > > I'd like to know more about why people/companies employ
> non-standard
> > > emergency numbers. If this is a safeguard against
> mis-dialing ("what
> > > am I to dial - 9-911 or 911 if always dial 9 to make
> external calls"
> > > - then gateways should be configured to strip extra prefix).
> >
> > Companies with large buildings or campuses may want to have a
> > non-standard emergency number. When help arrives at the
> front door,
> > someone from the company needs to be ready to lead the way to the
> > emergency.
> >
> > Allowing for the extra 9 is probably solely as a safeguard against
> > mis-dialing.
>
> My understanding is that in the US at least it's a simple
> rule: dialing
> 911 MUST work and MUST NOT go to anywhere but the local PSAP
> - it's not ok to divert those to the corporate security desk
> or anything.
One thing has always bothered me about phones sending INVITEs directly
to the gateway - perhaps somebody in this thread can shed some light on
this. Here it is... SipXecs offers an elaborate permission scheme to
restrict access to expensive resources (gateways for example) to only
those users that have the right permissions. This permissions scheme is
only good if a user is forced to go through the proxy to reach the
gateway. A malicious user that points his phone directly at the gateway
effectively bypasses all the permissions scheme inside sipXecs and is
free to make unpoliced calls using that gateway. To prevent such abuse,
one can create an Access Control List entry in the gateway that
stipulates that the gateway will only accept SIP messages from the
sipXecs (this is how our external trial gateway is configured for
example). If we allow phones to make emergency calls directly to the
gateway, does it mean that we can no longer have ACLs in the gateway
that will restrict who can place calls to the gateway? What strategy
will be used to allow phones to make emergency calls directly to the
gateway while only accepting non-emergency calls from the sipXecs?
_______________________________________________
sipx-dev mailing list
[email protected]
List Archive: http://list.sipfoundry.org/archive/sipx-dev
Unsubscribe: http://list.sipfoundry.org/mailman/listinfo/sipx-dev
