[VOIPSEC] DKIM Domain Key Identified Mail

[Randell Jesup]

Simon Horne <s.horne at isvo.net> writes:
[ re: sip-identity ]
>Ideally. This it what we're trying to port to SIP, the UA's act as their 
>own authentication service.:(
>
>Also I noticed that it may take 6 messages to authenticate both parties and 
>then on top of that you may have to download 2 certificates. If parties are 
>a distance apart (say 150ms delay) then it maybe in excess of 1.5 sec just 
>to authenticate each other, is that acceptable?

        1.5 seconds is significant, especially if it has to occur after
signalling the user.  If it's pre-ring, it's still problematic when added
on top of other existing delays, though perhaps not too large to be 
practical.  Part of the problem is that people are used to short delays
before ring, especially when wired (not on a cellphone).  Let's say that
there's a 1.5 second delay for call setup now (which BTW is probably 
over-generous). Adding 1.5 seconds to that is quite noticable and would be
getting into the annoying level for many people.

        I should note that 150ms is nowadays a fair distance apart for
broadband users (especially if you're talking one-way, which I think you
are).  We can typically go east-coast US to Taiwan in that time (actually
noticably less).

-- 
Randell Jesup, Worldgate (developers of the Ojo videophone), ex-Amiga OS team
rjesup at wgate.com