[Serusers] SER & PSTN gateways (Ovislink?)

[Tom]

On Wed, 24 Mar 2004, Alex Bligh wrote:

> --On 24 March 2004 10:27 -0800 Tom <tom at sdf.com> wrote:
>
> > DIGEST SIP security.
> > How does this work?
>
> Short answer: almost identically to HTTP authentication. IE a SIP request
> is sent, server replies with "authentication required" plus a a number (the
> challenge), the UA responds with a response containing a DIGEST calculation
> of the number, and the password. The SIP server then compares the digest
> response with its calculated digest based on the number plus the password.
> If they are equal, it grants access.
>
> Long answer: read the RFCs
>
> Alex

  I think UA auth is well understood due to it similarity to HTTP auth.
But how does a SIP server auth itself to a PSTN gateway?  Other than
host-based security, how does a PSTN gateway know that it is speaking to a
trusted SIP server?

  RFC3072, which covers a number of auth issues, really deals with the
proxy auth, not UA and gateway.  RF3329 deals with security between the UA
and the first hop SIP entity.


Tom