Re: [mpls-tp] [mpls] [PWE3] [AHMPLS-TP] Re: pollondraft-he-mpls-tp-csf-03.txt

["Eric Osborne (eosborne)" <[e-mail]>]

Inline with EO#

...

> >
> > John,
> >
> > Typically, IP will only detect a failure in a time scale of minutes.
> 
> I must not understand the point you're making.  For one thing, BFD is
> quite often configured to detect failures in significantly less than a
> minute.
> [JYL] The question is: Can we assume BFD is universally deployed for
IP
> and PW?
> If the answer is yes, then CSF is not needed, even for the PW
application.


EO#  There are three things that end users are going to carry over TP:
IP, MPLS and L2VPN.  L2VPN, as I understand it, has its own mechanism.
BFD implementations are stable and widely available for IP and MPLS and
interoperate across multiple vendors.  I would not say that BFD is
universally deployed, but that it is easily and universally deployable
for those who want it.

It does seem that we agree that CSF and BFD solve the same problem -
right?

> 
> > That is one reason why MPLS-TP OAM and Protection & Switching is
> needed.
> 
> What are others?
> [JYL] Maybe you'd better refer to RFC 5654 for a comprehensive reqs :)

EO#  My mistake, I read your email as "That is one reason why CSF is
needed"...that'll teach me to read too quickly. :)
I agree that OAM and Survivability (encompassing both protection and
restoration) are needed.  It is not obvious to me why this need for
OAM+S translates into an obvious and undeniable need for CSF.

Please note that I am neither for nor against CSF at this point - I'm
trying to understand what problem it solves that cannot already be
solved by tools which already exist.  So far it seems like we agree that
BFD is an appropriate tool for IP and MPLS networks - correct?

> 
> > I am not sure which mechanism in MPLS provides the CSF-like
> capability,
> > could you give more hints?
> 
> Even regular IGP/LDP hellos (no special tuning, no BFD) very
frequently
> are configured to detect failures in far less than "minutes".
> [JYL] Not sure this can be used to indicate the failure of  IP
service.
> Even so, do we need to firstly determine what protocol is carried and
then
> decide which mechanism could be used?


EO#  Not to get all layer-model-crazy, but if the client wants to detect
a failure the provider doesn't need to determine anything about the
carried protocol in order to allow them to do so.  In my experience no
matter what the provider tries to do for the client, the client will
always want to run their own liveness protocol over the provider's
network anyways.

Trust, but verify.  Or perhaps "trust, but not very much".





eric


> 
> 
> eric
> 
> >
> > Thanks
> > Yuanlong
> >
> > ----- Original Message -----
> > From: "John E Drake" <[e-mail]>
> > To: "Sprecher, Nurit (NSN - IL/Hod HaSharon)"
> <[e-mail]>om>;
> > "Yuanlong Jiang" <[e-mail]>om>; "Loa Andersson" <[e-mail]>nu>;
> > <[e-mail]>rg>; <[e-mail]>rg>; <[e-mail]>rg>; "MPLS-TP ad
hoc
> > team"
> > <[e-mail]>
> > Sent: Wednesday, December 01, 2010 9:29 PM
> > Subject: RE: [PWE3] [AHMPLS-TP] Re: [mpls-tp] poll
> ondraft-he-mpls-tp-csf-
> > 03.txt
> >
> >
> > > Nurit,
> > >
> > > As I understand the original requirement from Malcolm Betts, this
> > > capability is required for those cases in which a client is unable
> to
> > > detect the failure of its peer.  In MPLS-TP, we have three
clients,
> > > PW, IP, and MPLS, and I am quite sure that IP and MPLS clients can
> > > take care of themselves wrt detecting peer failure.
> > >
> > > Thanks,
> > >
> > > John
> > >
> > > Sent from my iPhone
> > >
> > >> -----Original Message-----
> > >> From: Sprecher, Nurit (NSN - IL/Hod HaSharon)
> > >> [mailto:[e-mail]]
> > >> Sent: Wednesday, December 01, 2010 4:47 AM
> > >> To: John E Drake; Yuanlong Jiang; Loa Andersson; [e-mail];
> mpls-
> > >> [e-mail]; [e-mail]; MPLS-TP ad hoc team
> > >> Subject: RE: [PWE3] [AHMPLS-TP] Re: [mpls-tp] poll
> > >> ondraft-he-mpls-tp- csf-03.txt
> > >>
> > >> But what about other client services... e.g. adapted by
service-LSP
> > >> and not by PWE3?
> > >>
> > >> -----Original Message-----
> > >> From: [e-mail] [mailto:[e-mail]] On
> Behalf
> > >> Of ext John E Drake
> > >> Sent: Wednesday, December 01, 2010 2:35 PM
> > >> To: Yuanlong Jiang; Loa Andersson; [e-mail];
[e-mail];
> > >> [e-mail]; MPLS-TP ad hoc team
> > >> Subject: Re: [PWE3] [AHMPLS-TP] Re: [mpls-tp] poll
> > >> ondraft-he-mpls-tp-csf-03.txt
> > >>
> > >> I am not convinced.  It seems like it belongs in the Pseudo Wire
> > >> application, which already has this capability.
> > >>
> > >> Sent from my iPhone
> > >>
> > >>
> > >> > -----Original Message-----
> > >> > From: Yuanlong Jiang [mailto:[e-mail]]
> > >> > Sent: Wednesday, December 01, 2010 1:07 AM
> > >> > To: Loa Andersson; [e-mail]; [e-mail];
> [e-mail];
> > >> > MPLS-TP ad hoc team
> > >> > Subject: [AHMPLS-TP] Re: [mpls-tp] poll on
draft-he-mpls-tp-csf-
> > >> 03.txt
> > >> >
> > >> > Support.
> > >> >
> > >> > I believe this mechanism is needed in MPLS-TP.
> > >> >
> > >> > Thanks
> > >> > Yuanlong
> > >> >
> > >> > ----- Original Message -----
> > >> > From: "Loa Andersson" <[e-mail]>
> > >> > To: <[e-mail]>rg>; <[e-mail]>rg>; <[e-mail]>rg>;
> "MPLS-TP
> > >> > ad hoc team" <[e-mail]>
> > >> > Sent: Thursday, November 18, 2010 7:56 PM
> > >> > Subject: [mpls-tp] poll on draft-he-mpls-tp-csf-03.txt
> > >> >
> > >> >
> > >> > > all,
> > >> > >
> > >> > > this is to start a two week poll on making
> > >> > >
> > >> > >
http://www.ietf.org/internet-drafts/draft-he-mpls-tp-csf-03.txt
> > >> > >
> > >> > > a mpls working group document.
> > >> > >
> > >> > > Please send comments support/not support to the mpls-tp
> maililng
> > >> > list.
> > >> > >
> > >> > > The poll ends Thursday Dec 2, 2010.
> > >> > >
> > >> > > /Loa
> > >> > > --
> > >> > >
> > >> > >
> > >> > > Loa Andersson                         email:
> > >> > [e-mail]
> > >> > > Sr Strategy and Standards Manager            [e-mail]
> > >> > > Ericsson Inc                          phone: [phone]
> > >> > >                                              [phone]
> > >> > > _______________________________________________
> > >> > > mpls-tp mailing list
> > >> > > [e-mail]
> > >> > > https://www.ietf.org/mailman/listinfo/mpls-tp
> > >>
> > >> _______________________________________________
> > >> pwe3 mailing list
> > >> [e-mail]
> > >> https://www.ietf.org/mailman/listinfo/pwe3
> > >
> >
> > _______________________________________________
> > mpls mailing list
> > [e-mail]
> > https://www.ietf.org/mailman/listinfo/mpls