Common link for both old and new LSP

fly · ‎03-31-2007

I read MPLS TE path reoptimization.

when found new resource, reoptimization occur. high end router will established a new LSP, at same time old LSP still there. here are some words from document:

"On links that are common to old and new LSPs, bandwidth is ?shared? and not allocated to the new LSP. Therefore, the new LSP will not be rejected on common links due to bandwidth constraints."

I don't know how to share common link for old and new LSP. because only after new LSP established the old one will be removed, they will coexist for a moment.

IF old LSP=New LSP=2M.they share 4M on common link , or share just 2M on common link?

fly · ‎03-31-2007

I just reread document, I understand new LSP will share bandwidth with old LSP, That means no new bandwidth will be needed.

But my qustion is how this is happened.