Technical Summary
Several methods in the Session Initiation Protocol can create an
association between endpoints known as a dialog. Some of these methods
can also create a different, but related, association within an existing
dialog. These multiple associations, or dialog usages, require carefully
coordinated processing as they have independent life-cycles, but share
common dialog state. Processing multiple dialog usages correctly is not
completely understood. What is understood is difficult to implement. This
memo argues that multiple dialog usages should be avoided. It discusses
alternatives to their use and clarifies essential behavior for elements
that cannot currently avoid them. This is an informative document and
makes no normative statements of any kind.
Working Group Summary
There was strong consensus within the WG that this was an important issue
that needed to be documented in an RFC.
Protocol Quality
Jon Peterson is the Responsible Area Director. The PROTO shepherd for the
document is Gonzalo Camarillo. Gen-ART review was provided by Pasi Eronen.
Note to RFC Editor
Section 5.4
OLD:
Target refresh requests update the remote target of a dialog when
they are successfully processed. The currently defined target
refresh requests are INVITE, UPDATE, SUBSCRIBE and NOTIFY (clarified
in a bug against RFC3565) and REFER (clarified in a bug against
RFC3515 [4]).
NEW:
Target refresh requests update the remote target of a dialog when
they are successfully processed. The currently defined target
refresh requests are INVITE, UPDATE, SUBSCRIBE, NOTIFY, and
REFER [4].