[mpls-tp] Linera Protection

Hello All,

I'm little confused related to what should be the behavior of Manual/Forced
switch operator commands related to protection switching. It will be really
helpful if someone can summarize what should be the difference between these
operator commands.

draft-ietf-mpls-tp-linear-protection-01 refers to RFC 4427 for the
definitions. But RFC 4427 has two definitions for Manual switchover. Manual
switch-over for normal traffic and Manual switch-over for recovery LSP/span.
Am i supposed to assume here that Manual switch-over refers to "Manual
switch-over for normal traffic"?

Also, as per the survavibility-fwk I could see these definitions:-

   o  Force protection action - a manual command that forces a switch of
normal data traffic to the recovery entity

   o  Manual protection action - a manual command that forces a switch of
data traffic to the recovery entity only when there is no
      defect in the recovery entity

>From these definitions I would take that "Forced switch" will switch to
the recovery entity from the working entity, eventhough the recovery
entity is in defect state. Is this right?

I could find some extensive state transition diagrams related to protection
switching in G.8031(Not sure if i'm supposed to refer this), as per this
state transition diagrams when the recovery entity is down even the Forced
switchover action is not allowed to switch from the working to recovery
entity.

Can someone please confirm on this?

Thanks,
Mahesh

On Sat, Jun 12, 2010 at 12:31 AM, Adrian Farrel <adrian@olddog.co.uk> wrote:

> Greg'n'Shahram,
>
> Please do check the terminology with the Survivability Framework.
> It is (just) not too late to tweak if we have got something wrong or left
> something out.
>
> cheers,
> Adrian
> ----- Original Message ----- From: "Greg Mirsky" <gregimirsky@gmail.com>
> To: "Shahram Davari" <davari@broadcom.com>
> Cc: "Mukund Mani" <mukund.mani@gmail.com>om>; <mpls-tp@ietf.org>
> Sent: Friday, June 11, 2010 8:02 PM
>
> Subject: Re: [mpls-tp] Demultiplexing to BFD sessions
>
>
> Hi Shahram,
>> yes, we need to settle on terminology related to protection.
>> It was discussed and presented at the last IETF meeting how bi-directional
>> BFD session easily can operate in, effectively, unidirectional mode. I
>> think
>> that operating BFD session in this mode is applicable to unidirectional
>> and
>> associated bi-directional p2p LSPs.
>>
>> Regards,
>> Greg
>>
>> On Fri, Jun 11, 2010 at 11:54 AM, Shahram Davari <davari@broadcom.com
>> >wrote:
>>
>>  Hi Greg,
>>>
>>>
>>>
>>> I assume by independent protection mode you mean unidirectional
>>> protection.
>>> If unidirectional protection is required, then it is simpler to not use
>>>  bidirectional BFD session.
>>>
>>>
>>>
>>> Regards,
>>>
>>> Shahram
>>>
>>>
>>>
>>> *From:* Greg Mirsky [mailto:gregimirsky@gmail.com]
>>> *Sent:* Friday, June 11, 2010 11:18 AM
>>> *To:* Shahram Davari
>>> *Cc:* Mach Chen; Mukund Mani; mpls-tp@ietf.org
>>>
>>> *Subject:* Re: [mpls-tp] Demultiplexing to BFD sessions
>>>
>>>
>>>
>>> Dear Shahram,
>>> assume one BFD session is applied to an associated bi-directional LSP.
>>> Then
>>> failure in one direction will bring the session in Down state which is
>>> not
>>> desired behavior for independent protection mode. Thus, I think, need for
>>> two BFD, in essence unidirectional, sessions.
>>>
>>> Regards,
>>> Greg
>>>
>>> On Fri, Jun 11, 2010 at 11:03 AM, Shahram Davari <davari@broadcom.com>
>>> wrote:
>>>
>>> Hi,
>>>
>>> Why would one need to run more than one BFD session over an LSP?
>>>
>>> Thanks,
>>> Shahram
>>>
>>>
>>> -----Original Message-----
>>> From: mpls-tp-bounces@ietf.org [mailto:mpls-tp-bounces@ietf.org] On
>>> Behalf
>>> Of Mach Chen
>>> Sent: Friday, June 11, 2010 3:05 AM
>>> To: Mukund Mani; mpls-tp@ietf.org
>>> Subject: Re: [mpls-tp] Demultiplexing to BFD sessions
>>>
>>> Hi Mukund,
>>>
>>> I also have the same question about this.
>>>
>>> As to the BFD discriminator, IMHO, we should keep using it as it be,
>>> because
>>> it may not be enough to demultiplex the BFD session only based on the
>>> label,
>>> this is especially true when there are more than two BFD sessions over
>>> the
>>> LSP.
>>>
>>> BTW, it seems that explicit null label distribution is not excluded (and
>>> IMHO it should be excluded as PHP) in MPLS-TP (do I miss something?) ,
>>> and
>>> it is one of the issues that LSP-Ping for BFD session bootstrap is trying
>>> to
>>> reslove.
>>>
>>> Best regards,
>>> Mach
>>>
>>> --------------------------------------------------
>>> From: "Mukund Mani" <mukund.mani@gmail.com>
>>> Sent: Friday, June 11, 2010 2:24 PM
>>> To: <mpls-tp@ietf.org>
>>> Subject: [mpls-tp] Demultiplexing to BFD sessions
>>>
>>> > Hi TP-Group
>>> > **
>>> > *draft-ietf-mpls-tp-lsp-ping-bfd-procedures-00 *states in Section 3
>>> >
>>> > "When using BFD over MPLS-TP LSPs, the BFD discriminator MUST either be
>>> > signaled via LSP-Ping or be statically configured."
>>> >
>>> > *draft-ietf-mpls-tp-bfd-cc-cv-00 *states in Section 3.5.6
>>> >
>>> > "MPLS labels at peer MEPs are used to provide context for the received
>>> BFD
>>> > packets."
>>> >
>>> > As I understand from the statement in the CC/CV draft, since
>>> discriminator
>>> > values are not required for demultiplexing to the BFD session anymore,
>>> > we
>>> > will not need LSP Ping to bootstrap BFD session for TP LSP.
>>> >
>>> > But *draft-ietf-mpls-tp-lsp-ping-bfd-procedures-00 *specifies that LSP
>>> > Ping
>>> > can also be used to signal BFD discriminator.
>>> >
>>> > So is LSP Ping still really needed in the context of BFD over MPLS-TP?
>>> >
>>> > Also as a part of MPLS-TP OAM could somebody explain why such a >
>>> deviation
>>> > is
>>> > taken from the BFD-BASE mode of demultiplexing which even BFD-MPLS uses
>>> > (discriminator values instead of MPLS labels), but MPLS-TP goes in for
>>> > demultiplexing using labels....
>>> >
>>> > Could somebody please clarify this..?
>>> >
>>> >
>>> > With Regards
>>> > Mukund
>>> > <http://tools.ietf.org/html/draft-ietf-mpls-tp-bfd-cc-cv-00>
>>> >
>>>
>>>
>>>
>>> > _______________________________________________
>>> > mpls-tp mailing list
>>> > mpls-tp@ietf.org
>>> > https://www.ietf.org/mailman/listinfo/mpls-tp
>>> >
>>> _______________________________________________
>>> mpls-tp mailing list
>>> mpls-tp@ietf.org
>>> https://www.ietf.org/mailman/listinfo/mpls-tp
>>>
>>>
>>> _______________________________________________
>>> mpls-tp mailing list
>>> mpls-tp@ietf.org
>>> https://www.ietf.org/mailman/listinfo/mpls-tp
>>>
>>>
>>>
>>>
>>
>
> --------------------------------------------------------------------------------
>
>
>
>
> _______________________________________________
>> mpls-tp mailing list
>> mpls-tp@ietf.org
>> https://www.ietf.org/mailman/listinfo/mpls-tp
>>
>>
> _______________________________________________
> mpls-tp mailing list
> mpls-tp@ietf.org
> https://www.ietf.org/mailman/listinfo/mpls-tp
>

[mpls-tp] Linera Protection - Operator commands terminology.