Re: [mpls-tp] Proposed liaison to ITU-T on G.8110

Yes,
Thanks for catching the problem.
Luca

David Sinicrope wrote:
> Agreed.
> Dave
>
>
> On 6/28/10 5:20 PM, "Andrew G. Malis" <agmalis@gmail.com> wrote:
>
> Stewart,
>
> That seems like a very reasonable liaison.
>
> Cheers,
> Andy
>
> On Mon, Jun 28, 2010 at 1:42 PM, Stewart Bryant <stbryant@cisco.com> wrote:
>   
>> Several people have pointed out a discrepancy in the model for MPLS as
>> documented in G.8110. Since this formal model plays a major role in the
>>  ITU-T MPLS-TP G.8110.1 specification, the error should to be corrected
>> before publication.
>>
>> I therefore propose that we send the following liaison to the ITU-T.
>>
>> - Stewart
>>
>> ===============
>>
>> To: ITU-T WP3/15
>> From: IETF
>>
>> Dear Dr. Trowbridge,
>>
>> We note that G.8110 is referenced as a normative reference from the draft
>> text of the revision of G.8110.1. We also note that G.8110 is
>> now five years old, and has received no contributions for update over that
>> period. G.8110 has been described as "not covering all of MPLS and certainly
>> not what has happened in the last five years."
>>
>> We believe that G.8110.1 should document MPLS-TP accurately. It is
>> important, therefore, that where the model for MPLS-TP differs from that
>> described in G.8110, the correct model be developed and documented in
>> G.8110.1.
>>
>> We would like to draw your attention in specifically to Section 6.2.2 of
>> G.8110 (and, in particular, Figures 1 and 2) that says that the Time-To-Live
>> (TTL) field of an MPLS header is part of the Characteristic Information (CI)
>> of an MPLS_CI traffic unit. We note that according to G.805, the CI is
>> supposed to be delivered end-to-end between MPLS APs without modification or
>> inspection. But the function of a TTL in an MPLS-TP network is to be
>> decremented at each hop along the path, and to be inspected at each hop and
>> tested against zero. Thus, in the model for MPLS-TP, the TTL should not form
>> part of the CI.
>>
>> We request that G.8110.1 be updated to include this revision to the model.
>> This might most easily be achieved by augmenting the references to G.8110
>> with updated figures based on those in G.8110 along with appropriate text
>> explaining the differences in the model such that G.8110.1 correctly
>> captures the model for MPLS-TP.
>>
>> ==========
>> _______________________________________________
>> mpls-tp mailing list
>> mpls-tp@ietf.org
>> https://www.ietf.org/mailman/listinfo/mpls-tp
>>
>>     
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