Re: [mpls] MPLS-RT review of draft-farbryantrel-mpls-retire-ach-tlv

["Adrian Farrel" <[e-mail]>]

Thanks Jia,

Your point is well taken and the Abstract in the working copy (ready to post)
now reads...

   The MPLS Generic Associated Channel (G-ACh) is a generalization of
   the applicability of the Pseudowire (PW) Associated Channel Header
   (ACH).  RFC 5586 defines the concept of TLV constructs that can be
   carried in messages on the G-ACh by placing them in the ACH between
   the fixed header fields and the G-ACh message.  These TLVs are called
   ACH TLVs

   No Associated Channel Type yet defined uses an ACH TLV.  Furthermore,
   it is believed that handling TLVs in hardware introduces significant
   problems to the fast-path, and since G-ACh messages are intended to
   be processed substantially in hardware, the use of TLVs in
   undesirable.

   This document updates RFC 5586 by retiring ACH TLVs and removing the
   associated registry.

Cheers,
Adrian

> -----Original Message-----
> From: Hejia (Jia) [mailto:[e-mail]]
> Sent: 23 May 2013 12:52
> To: Loa Andersson; Martin Vigoureux; draft-farbryantrel-mpls-retire-ach-
> [e-mail]; [e-mail]
> Cc: [e-mail]
> Subject: Re: MPLS-RT review of draft-farbryantrel-mpls-retire-ach-tlv
> 
> Hi,
> 
> I noticed a 01 version of draft-farbryantrel-mpls-retire-ach-tlv is available.
So I
> based my MPLS RT review on that version. I think the document is coherent,
> useful, technically sound and ready to be adopted as a WG draft. Just one
> comment:
> 
> 1) In the Abstract part, it is written as
> 
>    No Associated Channel Type yet defined uses a TLV. Furthermore, it
>    is believed that handling TLVs in hardware introduces significant
>    problems to the fast-path, and since G-ACh messages are intended to
>    be processed substantially in hardware, the use of TLVs in
>    undesirable.
> 
> The whole paragraph seems talking generally about TLVs for G-ACh messages,
> not specifically an ACH TLV. This might not be so accurate since we have some
G-
> ACh channel type using TLVs in its message, e.g. RFC 6428 defines a source
MEP-
> ID TLV for the MPLS-TP CV type which also requires hardware processing. I
think
> it might be better to simply say ACH TLV is not used and may cause additional
> processing which is not desirable. Or some better wording...
> 
> Thanks!
> 
> 
> B.R.
> Jia
> 
> 
> -----邮件原件-----
> 发件人: Loa Andersson [mailto:[e-mail]]
> 发送时间: 2013年5月8日 16:01
> 收件人: Lizhong Jin; Hejia (Jia); Gregory Mirsky; Eric Osborne (eosborne);
Martin
> Vigoureux
> 抄送: [e-mail]; mpls-
> [e-mail]
> 主题: MPLS-RT review of draft-farbryantrel-mpls-retire-ach-tlv
> 
> Jia, Lizhong, Greg and Eric,
> 
> You have been selected as an MPLS Review team reviewers for
> draft-farbryantrel-mpls-retire-ach-tlv-00.
> 
> Note to authors: You have been CC'd on this email so that you can know
> that this review is going on. However, please do not review your own
> document.
> 
> Reviews should comment on whether the document is coherent, is it
> useful (ie, is it likely to be actually useful in operational
> networks), and is the document technically sound?  We are interested
> in knowing whether the document is ready to be considered for WG
> adoption (ie, it doesn't have to be perfect at this point, but should be
> a good start).
> 
> Reviews should be sent to the document authors, WG co-chairs and
> WG secretary, and CC'd to the MPLS WG email list. If necessary, comments
> may be sent privately to only the WG chairs.
> 
> Are you able to review this draft by Mat 24, 2013?
> 
> Thanks, Loa
> (as MPLS WG chair)
> --
> 
> 
> Loa Andersson                        email: [e-mail]
> Senior MPLS Expert                          [e-mail]
> Huawei Technologies (consultant)     phone: [phone]