Subject: [Simple] On SIP-Specific event Notification new Draft

From: "Lamine Brahimi" <[email-masked]>
Date: Mon, 25 Feb 2002 15:49:26 +0100

Dear all,

Thanks for reporting me the new draft for SIP-Specific event Notification.

     If an initial SUBSCRIBE request is not sent on a pre-existing
     dialog, the subscriber will wait for a response to the SUBSCRIBE
     request or a matching NOTIFY.
     Responses are matched to such SUBSCRIBE requests if they contain
     the same the same "Call-ID", the same "From" header field, the
     same "To" header field, excluding the "tag", and the same "CSeq".
     Rules for the comparison of these headers are described in SIP
     [1]. If a 200-class response matches such a SUBSCRIBE request,
     it creates a new subscription and a new dialog (unless they have
     already been created by a matching NOTIFY request; see below).
          ........

So far, so good ....
However,

    If an initial SUBSCRIBE is sent on a pre-existing dialog, a
     matching 200-class response or successful NOTIFY request merely
     creates a new subscription associated with that dialog.
    Multiple subscriptions can be associated with a single dialog.

How an initial SUBSCRIBE can be sent on a pre-existing dialog otherwise
than sending to the same presentity
several times the SAME SUSBCRIBE ? As a consequence what is the benefit of
having multiple Subscriptions
in the same dialog ???

Thanks,
Lamine.