Re: [mpls] Question on the status of Y.1711 and RFC3429

[<neil.2.harrison at bt.com>]

Ping....to be clear here (given I was largely responsible for Y.1711):

-	Y.1711 (and before it the requirements given in Y.1710) was
based on trying to define a generic OAM solution for any correctly
specified co-ps mode layer network technology....the key principle
underpinning it was to 'keep things as simple as possible'.

-	If one breaks the architectural rules of what defines a
connection (eg must have single source) then there are no good/simple
OAM solutions.  Or more accurately, one cannot assign/manage resource in
a co-ps technology that breaks the rules of a connection.  BTW - One
cannot break this rule in the co-cs mode.  

-	The type of MPLS based on LDP creates merging mp2p constructs
(so does PHP on a last hop).  These are not connections.

-	LSP ping took something like 5-6 years and 13 or so
iterations....simple it is not.  The use of ECMP also greatly
complicates matters.

-	The OAM required to detect/handle defects in a properly
architected co-ps or co-cs mode layer network should be unidirectional
(and not of a request/response nature) for many reasons.....co-ps/cs
mode OAM is not like cl-ps mode OAM because connections create
constraining constructs under normal operation. 

So, having defined LDP (and PHP + ECMP) then Y.1711 is no good for this
type of MPLS....but this is not the fault of Y.1711 of course.  

regards, Neil

> -----Original Message-----
> From: mpls-bounces at ietf.org [mailto:mpls-bounces at ietf.org] On 
> Behalf Of Ping Pan
> Sent: 03 April 2008 14:48
> To: Shahram Davari
> Cc: 'Masayuki Takase'; mpls at ietf.org
> Subject: Re: [mpls] Question on the status of Y.1711 and RFC3429
> 
> 
> Have to bite:
> 
> Y.1711 may be the first to be defined, but LSP-ping was the 
> first to get 
> deployed and used to solve real problems. So the age, the 
> complexity and 
> the brand name sometimes do not matter much.
> 
> Why do we try this? (Maybe we have already). Let's lay out
> 
> - the problems that Y.1711 have solved where the existing mechanisms 
> defined in IETF won't be able to address, and
> 
> - how serious those problems are.
> 
> Then let's move from there.
> 
> - Ping
> 
> 
> Shahram Davari wrote:
> > Tom,
> > 
> > Could you please provide your definition of MPLS OAM? I have been 
> > involved in MPLS and OAM for more than 10 years and my 
> understanding 
> > is that Y.1711 is the first MPLS OAM defined in the industry.
> > 
> > -Shahram
> > 
> > -----Original Message-----
> > From: mpls-bounces at ietf.org [mailto:mpls-bounces at ietf.org] 
> On Behalf 
> > Of Thomas Nadeau
> > Sent: April-02-08 7:33 PM
> > To: Francesco Fondelli
> > Cc: mpls at ietf.org; Masayuki Takase
> > Subject: Re: [mpls] Question on the status of Y.1711 and RFC3429
> > 
> > 
> > 	ITU recommendation Y1711 has nothing to do with MPLS 
> OAM.  If you
> > want a
> > good overview of IETF MPLS OAM take a look at RFC4221.
> > 
> > 	--Tom
> > 
> > 
> > 
> > On Apr 2, 2008, at 11:09 AM, Francesco Fondelli wrote:
> >> On Wed, Apr 2, 2008 at 3:50 PM, Thomas Nadeau
> >> <tnadeau at lucidvision.com> wrote:
> >>>        How could you have built MPLS OAM to support label 14? Do
> >>> you mean
> >>> you implemented Y1711 using label 14?
> >>>
> >>>        --Tom
> >> Back in 2002/2003/2004? there used to be no 'T-' :-)
> >>
> >> http://www.itu.int/rec/T-REC-Y.1711/en
> >>
> >> "Y.1711: Operation & Maintenance mechanism for MPLS networks"
> >>
> >> Clear, isn't it? //I'm sarcastic
> >>
> >> Ciao
> >> FF
> >>
> > 
> > _______________________________________________
> > mpls mailing list
> > mpls at ietf.org
> > https://www.ietf.org/mailman/listinfo/mpls
> > 
> > _______________________________________________
> > mpls mailing list
> > mpls at ietf.org
> > https://www.ietf.org/mailman/listinfo/mpls
> > 
> _______________________________________________
> mpls mailing list
> mpls at ietf.org
> https://www.ietf.org/mailman/listinfo/mpls
> 
_______________________________________________
mpls mailing list
mpls at ietf.org
https://www.ietf.org/mailman/listinfo/mpls