RE: Proposal for Simplification of Overbooking

"sanford goldfless" <[email protected]> Tue, 10 Jun 2003 19:42:16 -0400
Newsgroups gmane.ietf.tewg
Message-ID <000001c32fa9$ed3a8640$6401a8c0@DASEP>
Wai Sum, Jerry -

I'm a little unclear as to your intention in the "integrated approach."  Is it
that the Local Overbooking Multiplier, instead of an independent representation
of a CT's overbooking policy (which is what the new term "OB(CTc)" would
signify), will now be rather a kind of correction factor, configured as needed
link by link, to other factors which are configured globally?

I think in general this wouldn't be a bad way to get compatibility with older TE
procedures. However, I'm still uncomfortable with how even network-wide per-CT
policies are supported using Link Size Overbooking.  And the integrated approach
appears to build on an understanding of how this is done: "For either per-domain
per-CT overbooking or per-link per-CT overbooking, we have Reserved(CTc) =
Tspec(LSPc) / OB(CTc)" and "OB(CTc) = LSOM * LSPOM(CTc) * LOM(CTc)."  

Specifically, how do you calculate Unreserved (CTc) using "LSPOM" when there are
per-CT policies and an aggregate constraint?  I don't see that BCc - Reserved
(CTc) / (LSOM * LSPOM) yields an effective value to advertise. After all, if CT7
has a policy of no overbooking, even though the link generally is allowed to be
overbooked, if BC7 = 50 and the CT's  reservation total is 50, then Unreserved
(CT7) should be 0.      

Thanks for clarifying, 
Sandy

Sanford Goldfless
192 Fuller St
Brookline MA 02446
617-738-1754
[email protected]


-----Original Message-----
From: Lai, Wai S (Waisum), ALABS [mailto:[email protected]] 
Sent: Tuesday, June 10, 2003 10:53 AM
To: Francois Le Faucheur (flefauch); Choudhury, Sanjaya; Dimitry Haskin; sanford
goldfless
Cc: Ash, Gerald R (Jerry), ALABS; Jim Boyle; Ed Kern
Subject: Proposal for Simplification of Overbooking

Attached is an I-D that provides more details on our proposal to simplify
overbooking from an operational perspective.  Before posting it, we would like
to hear your comments.
Thanks, Wai Sum and Jerry
winmail.dat (application/ms-tnef, 4.6 KB) - not displayed