sip-12----Page:5
1 2 3 4 5
|
What is the solution space? Strategy 1: Provide a causal trace of intermediary agency after the fact E.g., Request History (post-facto authorization at UAC) Each intermediary sending a backwards-direction NOTIFY (i.e., an implicit SUBSCRIBE) Strategy 2: Let the UAC explore new targets for a request rather than an intermediary E.g., Redirection (before the fact authorization at UAC) Spidering contacts via presence before sending a “real” request |