Re: [BLISS] Comments on draft-procter-bliss-call-park-extension-04 (Privacy Interactions)

["Dale Worley" <[e-mail]>]

On Tue, 2009-04-28 at 17:22 -0400, Orton, Scott (RICH1:B620) wrote:
> Lets take for example a case where Alice calls bob. Alice is using
> privacy as defined in RFC 3325. In this case the from header and the
> contact for Alice will anonymous. The contact is likely just an IP
> address and the from header will be sip:[e-mail].
> The contact header being an IP address is enough to exchange messages
> in a dialog but is unlikely to be enough to route a new call to the
> Alice. If it was enough then you privacy is not very good as nothing
> is preventing the user from returning a private call. 

If you want to use anything approaching "endpoint call control", that
is, anything more complex than an in-dialog REFER, then the anonymized
Contact has to route to Alice, or rather, the privacy service fronting
for Alice.  So it would have to be similar to a "temporary GRUU" (see
draft-ietf-sip-gruu-15), a URI which is secretly mapped to a unique
target but for only a limited time.

But assuming that the privacy service can provide such Contacts, I think
the proposed parking method (out-of-dialog REFER sent to the Park Server
so that it sends INVITE-with-Replace to the caller) should work.

Dale