Re: [CCAMP] [OSPF] draft-giacalone-ospf-te-express-path-01

Hi Acee,

John Drake and I did take a look at the draft mentioned in CCAMP.  It
had a large number of requirements and extensions to
a number of different protocols.  There is one sub-TLV (latency) that
appears the same - but the expectations
as to averaging vs. instantaneous were different.

The OSPF TE Express Path work is fairly self-contained and doesn't
specify in exact detail how the information
for the sub-TLVs is measured or obtained.  I think it could be used
for multiple purposes.

Alia

On Tue, Jun 21, 2011 at 12:49 PM, Acee Lindem <acee.lindem@ericsson.com> wrote:
> Hi Spencer (CCAMP copied as well),
>
> Here is a link for everyone's convenience:
>
> http://www.ietf.org/id/draft-giacalone-ospf-te-express-path-01.txt
>
> At IETF 80, there were questions about overlap with other CCAMP drafts containing interface delay metrics and proposals for new TE sub-TLVs. Have you or your co-authors, done looked at how your draft is positioned versus these other drafts? While these applications have differing goals, the CCAMP/OSPF chairs requested that this analysis be done.
>
> http://www.ietf.org/id/draft-wang-ccamp-latency-te-metric-03.txt
>
> We would like to avoid having exactly the same information advertised in two different link Sub-TLVs. I'd hope we could agree on common units.
>
> Thanks,
> Acee
>
> On Jun 20, 2011, at 4:30 PM, Spencer Giacalone wrote:
>
>> Hello everyone,
>>
>> As you may have noticed, another version of the OSPF TE Express Path
>> draft has been posted. We made a number of changes based on feedback
>> from IETF 80. We invite your comments and suggestions. The main
>> changes include:
>>
>> -We have consolidated some sub-TLVs for efficiency. There are no
>> longer nominal and anomalous sub-TLVs for delay and loss. The
>> functionality for signaling steady state verses abnormal performance
>> for these parameters have been moved into two sub-TLVs (where we used
>> to have four).
>>
>> -In order to advertise both normal and abnormal network performance
>> state in consolidated sub-TLVs, a bit, called the anomalous (A) but
>> has been added to certain sub-TLVs. The A bit is set when the measured
>> value of a parameter exceeds a configured maximum threshold. The A bit
>> is cleared when the measured value falls below its configured reuse
>> threshold. If the A bit is clear, the sub-TLV represents steady state
>> link performance.
>>
>> -We changed the encodings of certain variables from floating point to
>> fixed point. This change permits the addition of the A bit (when
>> necessary), it allows bit-space reservations to be made, and it
>> permits a common TLV format across the bulk of the TLVs in the draft.
>> In addition, the new encodings address concerns about granularity and
>> interoperability.
>>
>> -We added sub-TLVs for Residual Bandwidth and Available Bandwidth.
>> Residual bandwidth is defined as the Maximum Bandwidth [RFC3630] minus
>> the bandwidth currently allocated to RSVP-TE LSPs. Available bandwidth
>> is defined to be residual bandwidth minus the measured bandwidth used
>> for the actual forwarding of non-RSVP-TE LSP packets.
>>
>> -Various other modifications were made across the draft. These
>> include, but are not limited to, the abstract, the introduction, the
>> thresholding specifications, and a number of field descriptions.
>>
>> -Last, but certainly not least, Stefano Providi has joined the draft
>>
>> We look forward to hearing your comments and concerns.
>>
>> Thanks,
>>
>> Spencer, Alia, Dave, John, Stefano
>> _______________________________________________
>> OSPF mailing list
>> OSPF@ietf.org
>> https://www.ietf.org/mailman/listinfo/ospf
>
> _______________________________________________
> OSPF mailing list
> OSPF@ietf.org
> https://www.ietf.org/mailman/listinfo/ospf
>