Re: [CCAMP] Question on LSP control in draft-ietf-ccamp-mpls-tp-rsvpte-ext-associated-lsp-04.txt

["Rakesh Gandhi (rgandhi)" <[e-mail]>]

Thanks Fei for your reply. Please see inline..<RG>.

From: [e-mail] [mailto:[e-mail]]
Sent: Saturday, September 01, 2012 10:53 PM
To: Rakesh Gandhi (rgandhi)
Cc: [e-mail]; Lou Berger
Subject: Re: Question on LSP control in draft-ietf-ccamp-mpls-tp-rsvpte-ext-associated-lsp-04.txt


Hi Rakesh

See in line tagged with <fei>

Best regards

Fei

"Rakesh Gandhi (rgandhi)" <[e-mail]<mailto:[e-mail]>>

2012-08-31 21:49

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Lou Berger <[e-mail]<mailto:[e-mail]>>

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Question on LSP control in draft-ietf-ccamp-mpls-tp-rsvpte-ext-associated-lsp-04.txt







Hi Lou, Fei,

When an (originating) ingress node is provisioned with "5 (TBD)  Single Sided Associated Bidirectional LSPs  (A)" and wishes to control both forward and reverse  LSPs by adding "REVERSE_LSP" object, I would think that the ingress node needs to know about the signaling (path) errors (such as soft preemption or admission failure) on the reverse LSP.  Is there any text somewhere in an RFC/draft that describes how a mid-point node can send the signaling (path) error to the originating ingress node for the reverse LSP? Is there an assumption to use RSVP_NOTIFY message? Sorry if I had missed any previous discussion on this topic.

<fei> Please check http://tools.ietf.org/html/draft-ietf-ccamp-mpls-tp-rsvpte-ext-associated-lsp-04#section-3.2.9 to see whether we need to add more words here. :)

<RG> What I am referring to is as follows: forward LSP path from A (Ingress) - B ¨C C ¨C D (egress). Reverse LSP path is D ¨C E ¨C F ¨C A. Here node A is the initializing LSP ingress node and controls the path for reverse LSP by adding REVERSE_LSP object. So if there is a path error on the reverse LSP say on link F-E, the path error will be sent to head-end of that LSP which is node D. As path for the reverse LSP is controlled by node A, node A needs to know about this path error so it may compute an alternate path for the reverse LSP. Is there a mechanism somewhere defined for node D to relay this path error to initializing node A?
Thanks,
Rakesh

Thanks,
Rakesh