[VOIPSEC] VoIP Attack : How feasible

[Dan Wing]

> Dan Wing writes:
> > > 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).  
> 
> Thanks!  That was the missing piece of the puzzle for me.  To 
> make this so it doesn't trash the core network with work on 
> a failure, Host2 takes over Host1's core-facing identity.  I 
> failed to extract that bit of information from the draft.

The draft doesn't care much about what happens on the core
side -- it is only trying to establish a standard for the 
connection between the UA and its edge proxy/proxies.

> I'm much happier now. 

:-)

-d


> Geoff
> 
> -----Original Message-----
> From: Dan Wing [mailto:dwing at cisco.com] 
> Sent: Tuesday, July 25, 2006 1:42 PM
> To: Geoff Devine; 'DePietro, John'; 'Pankaj Shroff'
> Cc: Voipsec at voipsa.org
> Subject: RE: [VOIPSEC] VoIP Attack : How feasible
> 
> > 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