[VOIPSEC] VoIP Attack : How feasible

[Dan Wing]

> Doesn't this approach just create a registration storm when there is a
> failure? 

No, you're registered at both proxies all the time.  See section 3
of the Internet Draft.  It has a beautiful ASCII diagram:

       +-------------------+
       | Domain            |
       | Logical Proxy/Reg |
       |                   |
       |+-----+     +-----+|
       ||Host1|     |Host2||
       |+-----+     +-----+|
       +---\------------/--+
            \          /
             \        /
              \      /
               \    /
              +------+
              | User |
              | Agent|
              +------+

> The I-CSCF/Routing proxy has to be told that each of the
> clients moved to another edge proxy.

That is necessary whenever a P-CSCF (edge proxy) dies, unless
the "new" P-CSCF assumes the now-dead P-CSCF's identity (IP
address).  That can still be done with the scheme described
in sip-outbound.

-d


> Geoff
> 
> -----Original Message-----
> From: Dan Wing [mailto:dwing at cisco.com] 
> Sent: Tuesday, July 25, 2006 12:46 PM
> To: 'DePietro, John'; Geoff Devine; 'Pankaj Shroff'
> Cc: Voipsec at voipsa.org
> Subject: RE: [VOIPSEC] VoIP Attack : How feasible
> 
> > Regarding, sip-outbound's approach.  Do you have a 
> > description of this, draft-rfc or whitepaper? 
> 
> Sorry, I should have included a citation:
> http://www.ietf.org/internet-drafts/draft-ietf-sip-outbound-04.txt
> 
> -d