Dear Les,

Many thanks for your quick feedback. We are very appreciate all of your 
insightful comments and advices. ☺

Please let me clarify the one of requirements is that the ingress node cannot 
insert IFIT instruction for packets going into a path unless the egress node 
signals its capability of processing IFIT data fields.

Actually, taking your suggestions and those of others into account, we tried to 
use NETCONF for query node capability.  However, in the scenario of SR-BE, the 
ingress node controls a path along which packets are transmitted, which is not 
included in a centralized controller. Therefore, extensions to IGP for node’s 
capability advertisement is considered as an efficient way but NETCONF doesn't 

Best regards,

From: Les Ginsberg (ginsberg) []
Sent: Friday, July 17, 2020 5:25 AM
To: wangyali <>;
Subject: RE: New Version Notification for 

Yali -

While it is kind of you to acknowledge many of us for our comments, in many 
cases (myself included) what we told you is that this does not belong in the 

Putting out a new draft which continues to push for advertising ifit in IGPs 
(even if in different TLVs) does not indicate that you are heeding our message. 


> -----Original Message-----

> From: Lsr <<>> On Behalf Of 
> wangyali

> Sent: Thursday, July 16, 2020 8:20 AM

> To:<>

> Subject: [Lsr] FW: New Version Notification for draft-wang-lsr-igp-

> extensions-ifit-00.txt


> Dear LSR WG,


> We've uploaded a new revision of draft-wang-lsr-igp-extensions-ifit-00 to

> replace draft-wang-lsr-ifit-node-capability-advertisement. In this new

> revision, Node and Link Attribute TLVs are extended to IGP for signaling the

> supported IFIT capability of egress and/or intermediate nodes to the ingress

> nodes.


> The changes in this revision are:


> 1. added Link Attribute TLVs extension to IGP to signal IFIT Capability at 
> link

> granularity.

> 2. updated Application section, which illustrates such advertisements would

> helpful for avoiding the leak of IFIT-specific header and metadata, as well 
> as,

> for ingress routers to gather each router's IFIT capability for achieving the

> computation of TE paths or loose TE paths that be able to fulfill the 
> visibility of

> on-path OAM data.

> 3. updated Acknowledgements sections, in which, the authors would like to

> thank Acee Lindem, Christian Hopps, Robert Raszuk, Les Ginsberg, Jeff

> Tantsura, Rakesh Gandhi, Tony Li and Greg Mirsky for the comments.

> 4. adding China Telecom into the author list.


> We are looking forward to hearing your feedback and comments, and try to

> achieve consensus.


> Thanks,

> Yali



> -----Original Message-----

> From:<> 
> []

> Sent: Monday, July 13, 2020 9:15 PM

> To: Tianran Zhou <<>>; 
> wangyali

> <<>>; Huanan Chen 
> <<>>;

> Liumin (Lucy) <<>>; Ran 
> Pang

> <<>>; Liumin (Lucy) 
> <<>>

> Subject: New Version Notification for draft-wang-lsr-igp-extensions-ifit-

> 00.txt



> A new version of I-D, draft-wang-lsr-igp-extensions-ifit-00.txt

> has been successfully submitted by Yali Wang and posted to the IETF

> repository.


> Name:                               draft-wang-lsr-igp-extensions-ifit

> Revision:          00

> Title:                  IGP Extensions for In-situ Flow Information Telemetry 
> (IFIT)

> Capability Advertisement

> Document date:            2020-07-12

> Group:                              Individual Submission

> Pages:                               12

> URL:            

> extensions-ifit-00.txt<>

> Status:         

> ifit/<>

> Htmlized:       

> Htmlized:       

> extensions-ifit<>



> Abstract:

>    This document extends Node and Link Attribute TLVs to Interior

>    Gateway Protocols (IGP) to advertise supported In-situ Flow

>    Information Telemetry (IFIT) capabilities at node and/or link

>    granularity.  An ingress router cannot insert IFIT-Data-Fields for

>    packets going into a path unless an egress router has indicated via

>    signaling that it has the capability to process IFIT-Data-Fields.  In

>    addition, such advertisements would be useful for ingress routers to

>    gather each router's IFIT capability for achieving the computation of

>    Traffic Engineering (TE) paths or loose TE paths that be able to

>    fulfill the visibility of on-path OAM data.






> Please note that it may take a couple of minutes from the time of submission

> until the htmlized version and diff are available at


> The IETF Secretariat



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