RFC 2209 (rfc2209) - Page 2 of 25

Resource ReSerVation Protocol (RSVP) -- Version 1 Message Processing Rules

RFC 2209                RSVP-Message Processing           September 1997


        PSB contents include the following values from a PATH message:

        -    Session

        -    Sender_Template

        -    Sender_Tspec

        -    The previous hop IP address and the Logical Interface
             Handle (LIH) from a PHOP object

        -    The remaining IP TTL

        -    POLICY_DATA and/or ADSPEC objects (optional)

        -    Non_RSVP flag

        -    E_Police flag

        -    Local_Only flag

        In addition, the PSB contains the following information provided
        by routing: OutInterface_list, which is the list of outgoing
        interfaces for this (sender, destination), and IncInterface,
        which is the expected incoming interface.  For a unicast
        destination, OutInterface_list contains one entry and
        IncInterface is undefined.

        Note that there may be more than one PSB for the same (session,
        sender) pair but different incoming interfaces.  At most one of
        these, which will have the Local_Only flag off, will be the PSB
        used for forwarding PATH messages downstream; we will refer to
        it as the "forwarding PSB" in the following.  The other PSB's
        will have the Local_Only flag on and an empty
        OutInterface_list.h The Local_Only flag is needed to correctly
        match PSB's against RSB's, by the rules of [RFC 2205].

   o    RSB -- Reservation State Block

        Each RSB holds a reservation request that arrived in a
        particular RESV message, corresponding to the triple:  (session,
        next hop, Filter_spec_list).  Here "Filter_spec_list" may be a
        list of FILTER_SPECs (for SE style), a single FILTER_SPEC (FF
        style), or empty (WF style).  We define the virtual object type
        "FILTER_SPEC*" for such a data structure.






Braden & Zhang               Informational