Subject: RE: Ethernet over MPLS

From: "Andrew Smith" <[email-masked]>
Date: Mon, 17 Mar 2003 17:25:18 -0800

Luca,

Alternatively, it's time to reconsider whether the Tagged Mode is
justified at all. 

There's not a really good set of criteria that IETF uses for evaluating
this sort of thing: maybe it needs some. For what it's worth, IEEE 802
uses what many consider to be a good set of "5 criteria" that must be
met by any standard or feature of a standard. These include, with my
commentary on each added:
- distinct identity (don't publish two standards that achieve the same
goal, don't allow multiple options in one standard for achieving the
same goal).
- broad market potential (general purpose solutions - don't make
assumptions about how e.g. VLANs will be used in the future; don't
fragment the market by making customers choose between incompatible
options). 
- compatibility with other standards (e.g. don't place restrictions on
the ways in which existing standards can be used with this new one).
- technical feasibility (anything's possible - it's just software or
gates, right?).
- economic feasibility (backwards compatibility with pre-standard
implementations is *not* part of this criterion - the standard/feature
must stand on its own for new implementations).

I don't think Tagged Mode passes many of these test criteria: may I
start a call for getting rid of Tagged Mode? Does anyone else think it
doesn't belong here in this piece of work? Does it make it a "better"
standard for having it in there?

Andrew Smith

-----Original Message-----
From: [email-masked] [mailto:[email-masked]] On Behalf Of Luca
Martini
Sent: Monday, March 17, 2003 4:12 PM
To: [email-masked]
Cc: Shahram Davari; 'Ali Sajassi'; Andrew G. Malis; [email-masked];
Busschbach, Peter B (Peter); [email-masked]
Subject: Re: [PWE3] Ethernet over MPLS

Following this thread I understand the following two changes that will
be 
required to the draft text:

1) an explanation that Tagged mode may reorder frames <sa, da,
priority>.

2) Some re-wording of the raw mode vs tagged mode text.
Can somebody suggest some simple text  for this point ?

Thanks.
Luca

Vach Kompella wrote:
>>From: Shahram Davari [mailto:[email-masked]]
>>
>>>Yes, everything is possible with the raw mode.
>>>
>>
>>I can't understand. If you agree that the raw mode can satisfy the
>>requirement in which one of the PEs can't push/pop, then why is there
>>a need for tagged mode?
>>
> 
> 
> Because there are PEs that cannot do some NSP functions.
> 
> 
>>-Shahram
> 
> 
> -Vach 
> 
> _______________________________________________
> pwe3 mailing list
> [email-masked]
> https://www1.ietf.org/mailman/listinfo/pwe3
> 

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---

From: Muneyoshi Suzuki <[email-masked]>
Date: Wed, 19 Mar 2003 11:19:06 +0900

> I don't think Tagged Mode passes many of these test criteria: 

I fully agree with this statement.

I would strongly suggest the WG to carefully investigate consistency 
with IEEE standards as well as ITU-T recommendations. It seems to me,
PWE3 is violating many existing specifications.

Thanks,

Muneyoshi Suzuki
Nippon Telegraph and Telephone Corp.