Re: [mpls] On Up and Down MEP in MPLS-TP (RE: 2nd working grouplast call o

["Shahram Davari" <[e-mail]>]

Hideki,

Correct, but such LSP that can only accept packets from a single interface is very niche application and not generic enough to define an UPMEP for it. We need a definition that is applicable to LSPs in general.

Thx
SD

-----Original Message-----
From: [e-mail] [mailto:[e-mail]] 
Sent: Wednesday, March 13, 2013 3:31 PM
To: Shahram Davari
Cc: [e-mail]; [e-mail]; [e-mail]; [e-mail]; [e-mail]
Subject: Re:RE: On Up and Down MEP in MPLS-TP (RE: [mpls] 2nd working grouplast call o

Sharam,

Very simple question.

>Assume there are 2 ingress interfaces A & B. Each interface maps Ethernet traffic
>to its own PW (PW-A and PW-B). Now assume both these PWs go inside the same LSP that exists Interface C. 
Why is this assumption mandatory?

"Assume there are 1 ingress interfaces A. Two VLAN flows in the interface A are mapped
 to different PWs (PW-A and PW-B). Now assume both these PWs go inside the same LSP."
In this case, UP-MEP of the LSP can be at interface A, right?

Thanks,
Hideki Endo


>Greg,
>
>RFC6371 is very high level and does not define whether UP MEP applies to LSP or PW.  Assume there are 2 ingress interfaces A & B. Each interface maps Ethernet traffic to its own PW (PW-A and PW-B). Now assume both these PWs go inside the same LSP that exists Interface C. Now please explain if we were to have an UP-MEP for LSP then on which interface would that LSP UP-MEP reside? Interface A? B? C?
>
>This simple example shows you can't have an LSP UP-MEP.
>
>Thx
>SD
>
>From: Gregory Mirsky [mailto:[e-mail]]
>Sent: Tuesday, March 12, 2013 11:56 AM
>To: Shahram Davari; [e-mail]
>Cc: [e-mail]; [e-mail]; [e-mail]; [e-mail]
>Subject: On Up and Down MEP in MPLS-TP (RE: [mpls] 2nd working group last call ondraft-ietf-mpls-tp-mip-mep-map)
>
>Dear All,
>What would be the most appropriate subject to continue this discussion? I'll give it a try, please feel free to change it.
>
>I think that there's nothing that can preclude from supporting UP MEP on MPLS-TP LSP, according to UP MEP definition of RFC 6371, even when multpiple PWs mapped to that LSP. Same, I think, is the true for  p2mp PW. Note that service, VPWS, is not part of MPLS-TP architecture.
>
>        Regards,
>                Greg
>
>-----Original Message-----
>From: [e-mail]<mailto:[e-mail]> [mailto:[e-mail]] On Behalf Of Shahram Davari
>Sent: Tuesday, March 12, 2013 11:30 AM
>To: [e-mail]<mailto:[e-mail]>
>Cc: [e-mail]<mailto:[e-mail]>; [e-mail]<mailto:[e-mail]>; [e-mail]<mailto:[e-mail]>; [e-mail]<mailto:[e-mail]>
>Subject: Re: [mpls] 2nd working group last call ondraft-ietf-mpls-tp-mip-mep-map
>
>Hideki,
>
>So far no RFC or draft has talked about Down or UP MEP for LSPs. But if you think about it logically LSPs can't have UP-MEP because LSP can carry many PWs and each PW may enter the LSP from a different port/interface.  PWs can have UP-MEP but only for P2P services (VPWS), otherwise they can't have UP-MEP either (same as LSP).
>
>My suggestion is to correct figures and change UP-MEPs to Down-MEPs for LSPs. Also to mention UP-MEP is out of scope.
>
>Thx
>SD
>
>-----Original Message-----
>From: [e-mail]<mailto:[e-mail]> [mailto:[e-mail]]
>Sent: Tuesday, March 12, 2013 11:20 AM
>To: Shahram Davari
>Cc: [e-mail]<mailto:[e-mail]>; [e-mail]<mailto:[e-mail]>; [e-mail]<mailto:[e-mail]>; [e-mail]<mailto:[e-mail]>; [e-mail]<mailto:[e-mail]>
>Subject: Re:Re: [mpls] 2nd working group last call ondraft-ietf-mpls-tp-mip-mep-map
>
>Hi Shahram,
>
>Just one comment.
>
>>I would also argue that LSPs can't have UP-MEPs, since PWs from many ingress ports can enter an LSP  and therefore the LSP can't start on the ingress interface.
>
>I think this depends on implementations.
>Any RFC don't restrict to DOWN-MEPs in an LSP.
>
>Anyway, MEP mechanism is out of scope in this draft as you said.
>
>Thanks,
>Hideki Endo
>
>>Hi,
>>
>>Although I mentioned I am Ok with the draft to be advanced to RFC, but after reviewing it in more details it appears that the draft, in spite of its name, does talk about UP-MEP at all and only talks about UP-MIP, while the figures show UP-MEPs for LSPs.  Even if the scope of the draft is UP-MIP, considering that there can't be a MIP without a MEP,  the draft should have some wording regarding UP-MEPs and their applicability to LSPs and PWs. I would also argue that LSPs can't have UP-MEPs, since PWs from many ingress ports can enter an LSP  and therefore the LSP can't start on the ingress interface.
>>
>>A quick fix at this point is to mention UP-MEP is out of scope and change the figures to only show Down-MEPs. A better fix is to elaborate on UP-MEP and its applicability and placement, etc.
>>
>>Regards,
>>Shahram
>>
>>
>>
>>-----Original Message-----
>>From: [e-mail]<mailto:[e-mail]> [mailto:[e-mail]] On Behalf Of
>>Shahram Davari
>>Sent: Wednesday, March 06, 2013 11:30 AM
>>To: Loa Andersson; [e-mail]<mailto:[e-mail]>
>>Cc: <[e-mail]<mailto:[e-mail]>>; [e-mail]<mailto:[e-mail]>;
>>[e-mail]<mailto:[e-mail]>
>>Subject: Re: [mpls] 2nd working group last call on
>>draft-ietf-mpls-tp-mip-mep-map
>>
>>My Comments are addressed and I support this draft to be published as Informational  RFC.
>>
>>Thx
>>Shahram
>>
>>-----Original Message-----
>>From: [e-mail]<mailto:[e-mail]> [mailto:[e-mail]] On Behalf Of
>>Loa Andersson
>>Sent: Tuesday, February 26, 2013 3:02 AM
>>To: [e-mail]<mailto:[e-mail]>
>>Cc: <[e-mail]<mailto:[e-mail]>>; [e-mail]<mailto:[e-mail]>;
>>[e-mail]<mailto:[e-mail]>
>>Subject: [mpls] 2nd working group last call on
>>draft-ietf-mpls-tp-mip-mep-map
>>
>>Working Group,
>>
>>draft-ietf-mpls-tp-mip-mep-map-05.txt has been updated after a previous
>>last call, due to the nature a and extent of the updates we have chosen
>>to start a 2nd wg last call.
>>
>>The IETF datatracker status page for this draft is:
>>https://datatracker.ietf.org/doc/draft-ietf-mpls-tp-mip-mep-map
>>
>>There's also a htmlized version available at:
>>http://tools.ietf.org/html/draft-ietf-mpls-tp-mip-mep-map-05
>>
>>A diff from the previous version is available at:
>>http://www.ietf.org/rfcdiff?url2=draft-ietf-mpls-tp-mip-mep-map-05
>>
>>Please send your comments, including approval of the documents and the
>>updates to the mpls working group list ([e-mail]<mailto:[e-mail]>)
>>
>>This working group last call ends March 13, 2013.
>>
>>/Loa
>>for the MPLS working group co-chairs
>>--
>>
>>
>>Loa Andersson                        email: [e-mail]<mailto:[e-mail]>
>>Senior MPLS Expert                          [e-mail]<mailto:[e-mail]>
>>Huawei Technologies (consult)        phone: [phone]
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