Subject: RSVP flowspecs merging

From: [email-masked]
Date: Tue, 30 Jan 2001 12:04:44 -0800

Hi all,

     I have the following basic question about flowspecs merging in RSVP.
     Consider the following scenario.

(See attached file: rsvp-merging.txt)

     Suppose the Tspec in the PATH messge from S1 is B; Tspec from S2 is 2B.
     The flowspec in the RESV message from D1 is SE(S2) {2B}; the flowspec from
D2 is SE(S1,S2){B}. These two flowspecs will be merged at R2.  So R2 will send
a RESV message to R1 with SE(S1,S2){2B}.
     Now, when R1 sends a RESV message to R0, will it send SE(S1){B} or
SE(S1){2B}? The question is "When a router sends a RESV message upstream, does
it take into account the Tspecs from senders in that upstream direction?"
     If the answer is YES, can you point me to the specific rule in RFC2205 or
RFC2209 that describes the computation?

     Thanks.

-- James Huang

---

From: Bob Braden <[email-masked]>
Date: Tue, 30 Jan 2001 20:22:34 GMT

The question is "When a router sends a RESV message upstream, does
  *> it take into account the Tspecs from senders in that upstream direction?"
  *>      If the answer is YES, can you point me to the specific rule in RFC2205 or
  *> RFC2209 that describes the computation?
  *> 
  *>      Thanks.
  *> 
  *> -- James Huang
  *> 

James,

NO.  But the same effect is achieved by bullet 3. in section 2.2
of rfc 2205: {2B} is sent upstream, but at the upstream node,
it installs a reservation for min(B, 2B).

Bob Braden