[VOIPSEC] Why a secure keyechange for media encryption?

[Hadriel Kaplan]

Depends on how and through what.  Service providers use many boxes that
either need to see inside the SDP, or need to change it.  SBCs, media
servers, transcoders, etc., often change it (though they don't have to in
all cases).  Some "session managers" need to see it though probably not
change it.  (of course that term is ambiguous and all the other devices
listed also do session management, but people are starting to separate the
term so that companies which only build session managers have a chance :)

So your call may not work through service providers using s/mime. 

And then there's the Certificate issue, PKI, etc.

Lastly, hardly any phones or gateways support it, so you won't get much
success for your trouble.  

-hadriel


> -----Original Message-----
> From: Michael Prochaska [mailto:tm021090 at fh-stpoelten.ac.at]
> Sent: Friday, April 28, 2006 12:51 PM
> To: Hadriel Kaplan
>
> > Send signaling directly to the far-end, or use s/mime to
> > encrypt the SDP (good luck with that).
> 
> is it problematic to encrypt the SDP with S/MIME in your mind?