Re: [mpls] MPLS-RT review of draft-bryant-mpls-rfc6374-sfl

["lizho.jin" <[e-mail]>]

Hi,

I review this draft, and also the two related SFL draft. Overall, this document is useful and technically sound. And I have some non-blocking comments listed below. Regarding the adoption, I suggest to consider adopting draft-bryant-mpls-sfl-framework-03 first, then this draft which is highly relied on the concept of SFL.

Section 3

   The data service packets of the flow being instrumented are grouped

   into batches, and all the packets within a batch are marked with the

   SFL [I-D.ietf-mpls-flow-ident]

[Lizhong] more suitable to refer [draft-bryant-mpls-sfl-framework], not [I-D.ietf-mpls-flow-ident]

Section 4

   Such a packet may not need to be carried over an SFL since the delay

   over a particular LSP should be a function of the TC bits.

[Lizhong] not understand here, adding SFL does not change the LSE and TC, why not possible to carry over SFL?

 

Section 7

7.  Multiple Packet Delay Characteristics

[Lizhong] is it assumed here that all packets belong to one flow will go through the same path? Some network equipment may not be the case. E.g., case in RFC7424.

Section 7.1

   There will be a number of Interval/Number pairs depending on the

   number of buckets being specified by the Querier.  If an RFC6374

   message is being used to configure the buckets, the Responder MUST

   respond with 0 packets in each bucket until it has been configured

   for a full measurement period (i.e. it was configured at the time of

   the last response message).  Out of band configuration is permitted

   by this mode of operation.

[Lizhong] need detail process of Query and Reponse. E.g., does the query need "Number pkts in Bucket" field, and if not, please specify.

7.3.1.  RFC6374 Multi-Packet Delay Measurement Message Format

[Lizhong] this is only for Classic Standard Deviation, right? why it is not section 7.2.1?

7.4

   This RFC6374 message is carried over an LSP in the way described in

   [RFC6374] and over an LSP with an SFL as described in Section 9

[Lizhong] what's the format of query message, will it include "Time of First Packet", "Time of First Packet", and other fields?

13.1.  Allocation of PW Associated Channel Type

   As per the IANA considerations in [RFC5586], IANA is requested to

   allocate the following Channel Type in the "PW Associated Channel

   Type" registry:

   Value  Description                    TLV Follows  Reference

   -----  -----------------------------  -----------  ---------

   TBD    Description MPLS Multi-Packet  No           This

          Delay Measurement

[Lizhong] there is other two message type need to be defined here. E.g., Bucket Jitter Measurement Message Format, Average Delay Measurement Message Format

Regards

Lizhong

On 03/9/2017 11:09，Loa Andersson<[e-mail]> wrote：

Huub, Andy, Vishwas and Lizhong,

You have been selected as MPLS-RT reviewers for 
draft-bryant-mpls-rfc6374-sfl-03.

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), 
nd 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). Please remember that it often is
easier to progress the document when it has become a working group
document. All comments in the MPLS-RT review needs to be addressed,
but please think carefully about whether a comment is gating the
adoption or could just as easily be addressed after the adoption.

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.

If you have technical comments you should try to be explicit about what
needs to be resolved before adopting it as a working group document, and
what can wait until the document is a working group document and the
working group has the revision control.

Are you able to review this draft by March 23, 2017? Please respond
whether you are available to do the review in a timely fashion.


Thanks, Loa
(as MPLS WG co-chair)
-- 


Loa Andersson                        email: [e-mail]
Senior MPLS Expert                          [e-mail]
Huawei Technologies (consultant)     phone: [phone]