Subject: Refresh Reduction = RE: [Tsvwg] WGLC fordraft-ietf-tsvwg-rsvp-ipsec-00.txt NOW

From: "Francois Le Faucheur \(flefauch\)" <[email-masked]>
Date: Thu, 18 May 2006 15:56:26 +0200

Hello again Alexander,

>> Another proposition concerns the extended vDstPort. It is 
>> mentioned that it
>> is "normally set to all zeroes". 

Actually, that text probably needs some tweaking. 
It is normally set to zero IF the session needs to be shared across
multiple Aggregators (eg if the reservation is to be shared across
multiple aggregators). However, I believe each aggregator would normally
want a separate reservation and thus should write its IP address in
there.
I will think/discuss more about that and propose some edits to reflect
that.

>>Is it logical to send zeros 
>> (16 bytes in
>> the case of IPv6)? Furthermore, while sending the refresh 
>> PATH messages we
>> can reduce the overhead. I realize that one can use the RSVP refresh
>> reduction, but it is just recommendation, not obligation. 
>> So, the solution
>> is to introduce another C-Type that will correspond to the
>> GENERIC-AGGREGATE-IPv6/v4 SESSION without the extended 
>> vDstPort field.

Considering that, [In light of what I said above] the common case will
be that the field actually contains a meaningful information (ie
non-zero) and that there is a refresh reduction mechanism available
which would reduce the overhead orders of magnitude more, it doesn't
seem worth defining/handling yet another session type. This would just
save one field in a minority of cases. Would you agree?

>> Also, I have implemented the aggregated RSVP reservations 
>> for the NS-2
>> simulator. 

Nice!

Cheers

Francois

PS: Thanks for your review/comments and giving this spec the benefits of
your RFC3175 implementation experience.