RE: A quick question on http://www.ietf.org/internet-drafts/draft-ietf-ccamp-gmpls-recovery-e2e-signaling-03.txt

["Zafar Ali \(zali\)" <zali@cisco.com>]

 

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From: Dimitri.Papadimitriou@alcatel.be [mailto:Dimitri.Papadimitriou@alcatel.be]
Sent: Tuesday, December 20, 2005 8:05 AM
To: Zafar Ali (zali)
Cc: Adrian Farrel; ccamp@ops.ietf.org; owner-ccamp@ops.ietf.org
Subject: Re: A quick question on http://www.ietf.org/internet-drafts/draft-ietf-ccamp-gmpls-recovery-e2e-signaling-03.txt

zafar, i am not sure to fully understand your question

the O-bit is used for 1+1 and 1:1 protection scheme such as to have an indication when a protecting LSP is carrying the "normal" traffic after protection switching (so it applies only in case of 1+1 LSP uni-/bidirectional protection or 1:1 LSP protection)  .

 

Dimitri,

 

More specifically, my question was mainly on what "LSP (Protection Type) Flags" to use for, dedicated 1:1 protection, where

• Traffic is NOT duplicated at working and protecting LSP-es (i.e., this is not 1+1 protection),
• There is NO extra traffic on the protecting LSP (i.e., it's dedicated protection),

In this case there is NO duplication of the traffic on the backup resource (it's NOT 1+1). There is also NO extra traffic that protection resources carry.

 

Thanks

 

Regards... Zafar

 

 

thanks,
- dimitri.

ps: purpose is not to "contrast" between protection schemes

"Zafar Ali \(zali\)" <zali@cisco.com> Sent by: owner-ccamp@ops.ietf.org 19/12/2005 23:10

To:        <ccamp@ops.ietf.org>         cc:        "Adrian Farrel" <adrian@olddog.co.uk>, Dimitri PAPADIMITRIOU/BE/ALCATEL@ALCATEL         Subject:        A quick question on http://www.ietf.org/internet-drafts/draft-ietf-ccamp-gmpls-recovery-e2e-signaling-03.txt

Hi All,
 
It's a bit confusing how one would encode protection object for dedicated 1:1 protection (without traffic duplication) and I thought it deserves a confirmation.
 
I just wanted to confirm that to signal an LSP that is dedicated 1:1 protection, where

• Traffic is NOT duplicated at working and protecting LSP-es (i.e., this is not 1+1 protection),
• There is NO extra traffic on the protecting LSP (i.e., it's dedicated protection),

we are expected to:

• Set O-bit in protection object to 1 in signaling protecting LSP, to indicate that the protecting LSP is (only) carrying the normal traffic after protection switching (i.e., It's NOT 1+1 setup). If contrasting 1:1 with 1+1 is NOT the intended use of O-bit, what is the intended use.
• LSP (Protection Type) Flags to 0x10 = 1+1 Bi-directional Protection (for GMPLS optical LSPs). I.e., this is a dedicated protection.

If above is not the intended use of O-bit, I am not sure why O-bit is defined (as protection LSP is expected to carry normal traffic after switchover). In which is it expected to use 0x04 = 1:N Protection with Extra-Traffic as LSP (Protection Type) Flags?
 
Thanks
 
Regards... Zafar