Subject: RE: Network authentication

From: Scott Cadzow <[email-masked]>
Date: Fri, 5 Nov 1999 11:44:21 -0000

I would endorse Stephen's second point. Do the analysis at the service level
to get the service secure, then make the service to transport analysis and
get that secure. Choosing TLS or anything else without knowing why is a
route to doom.

Scott

-----Original Message-----
From: Stephen Thomas [mailto:[email-masked]]
Sent: 05 November 1999 12:27
To: Michael Thomas; Henning Schulzrinne
Cc: Michael Thomas; Dean Willis; Gonzalo Camarillo;
[email-masked]
Subject: Re: Network authentication

|  > Many SIP implementations can use either UDP or TCP. Indeed, one reason
|  > for supporting TCP (besides signaling trunks) is the ability to use
SSL.
|  > Use of SSL over UDP hasn't been done yet, although I don't see this as
|  > requiring more than dealing with mapping SSL messages to UDP datagrams.
|
|    This strikes me as the tail wagging the dog.
|    A deployment should choose a transport and then
|    figure out how to secure it rather than the
|    other way around.

A couple of thoughts on this thread:

1) Actually, there is a variation of TLS defined for UDP. It's the
   Wireless TLS standard developed by the Wireless Application
   Forum (www.wapforum.org). I don't know if anyone has actually
   implemented it.

2) I could make the argument that any real commercial deployment
   should first figure out its security requirements, then
   decide the security infrastructure, and, only then, determine
   the transport approach that fits within that security
   infrastructure. Leaving security as an afterthought has
   gotten a lot of people in trouble in the past. In this
   context it's worth noting that 40+ years of practical
   experience has unequivocally shown that there is a strong
   incentive for folks to try to get "free phone calls."

Stephen