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

[Dimitri.Papadimitriou@alcatel.be]

zafar
 
> 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. 
  
as pointed into the document for the
1:1 LSP protection:

   "Although the resources
for the protecting LSP are pre-allocated, 
   preemptable traffic may be carried end-to-end using this LSP. Thus,
   the protecting LSP is capable of carrying extra-traffic with the
   caveat that this traffic will be preempted if the working LSP fails."
 

hope this clarifies (i.e. there is
no specific flag when there is no extra-traffic)

> 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