The MPLS WG Archive[Date Prev][Date Next][Thread Prev][Thread Next] [Date Index][Thread Index][Author Index][Subject Index] [mpls] RE: [PWE3] Re: Y.1720 liased text
Adrain and Stewart, It seems to me the discussion about an issue in Y.1720 which has been in the public domain for a long time. In order to resolve the issue I suggest that a contribution be submitted to the next Q9/15 meeting ( either 12th., Feb or 10th.,April meetings). Q9/15 can discuss the issue and may recommend a way forward. Ghani ________________________________ From: Adrian Farrel [mailto:adrian@olddog.co.uk] Sent: Fri 26/01/2007 15:39 To: Huub van Helvoort; Stewart Bryant Cc: neil.2.harrison@bt.com; Ghani Abbas (BE/ETL); pwe3@ietf.org; mpls@ietf.org Subject: Re: [PWE3] Re: Y.1720 liased text Hi Huub, >> The implication of the text is that you can have a packet of the >> form: >> >> LSE (RFC3032) >> Sequence number >> LSE (RFC3032) >> Payload >> >> Is that correct? > > This is also what I read, and apparently Neil does as well. > >> If so what is the setting of the S bit (See RFC3032) in each >> case? > > Because the text does not mention any altering of the S-bit > I assume they do not change. Ah, so either setting of the S-bit is allowed? > I agree with Neil (see his 2002 post) that this requires a > very carefull configuartion of the network. Checking that > both ends support this feature and closely guard the connectivity > for both diverse routes. With the S-bit, careful config is needed. Without the S-bit it seems like a router that popped a label would expect the next thing on the stack to also be a label, but would actually find a magic sequence number. Although you could config around this (since the pop action must be installed) this is a new MPLS behavior. At the least it is a new LFIB action that is not previously described in any MPLS documentation. > Note that this text is in an appendix, so it does not form > an integral part of the recommendation, i.e. it is not mandatory. Hmmm. Shouldn't there be a specification of: - what must be supported - what can also be attempted I think Stewart's question is quite helpful here. Do we have any idea of what deployed implementations do? Cheers, Adrian _______________________________________________ mpls mailing list mpls@lists.ietf.org https://www1.ietf.org/mailman/listinfo/mpls
|
|