Re: [sfc] Few Querries from draft-agv-sfc-packet-delay-measurement-00

[nobin mathew <[e-mail]>]

Hi Gaurav,
Thank you for addressing my suggestions. I will go through the updated drafts and let you know if I have some more queries.
Regards
Nobin

-----Original Message-----
From: "Gaurav agrawal" <[e-mail]>
Sent: ‎6/‎29/‎2016 13:07
To: "Nobin Mathew" <[e-mail]>
Cc: "Anil Kumar S N (VRP Network BL)" <[e-mail]>; "VinodS Kumar" <[e-mail]>; "[e-mail]" <[e-mail]>; "[e-mail]" <[e-mail]>
Subject: RE: [sfc] Few Querries from draft-agv-sfc-packet-delay-measurement-00

Hi Nobin,
 
Please find the in-line response [Gaurav-2]
 
Also we have revised the draft, kindly review the new versions
 
https://datatracker.ietf.org/doc/draft-agv-sfc-performance-measurement-architecture/
https://tools.ietf.org/html/draft-agv-sfc-packet-delay-measurement-01
https://datatracker.ietf.org/doc/draft-agv-sfc-packet-loss-measurement/
 
Thanks and Regards,
Gaurav
 
From: Nobin Mathew [mailto:[e-mail]] 
Sent: 2016年6月28日 16:06
To: Gaurav agrawal
Cc: Anil Kumar S N (VRP Network BL); VinodS Kumar; [e-mail]
Subject: Re: [sfc] Few Querries from draft-agv-sfc-packet-delay-measurement-00
 
Hi Gaurav,
Thank you for the clarification. I have few more queries, please find them in-line. [tag: NOBIN-1]
Please address these points in both packet-delay and packet-loss measurement drafts.
 
On Tue, Jun 28, 2016 at 11:35 AM, Gaurav agrawal <[e-mail]> wrote:
Hi Nobin,
 
Thanks for your comments, please find the response in-line.
 
From: Nobin Mathew [mailto:[e-mail]] 
Sent: 2016年4月20日 18:35
To: Anil Kumar S N (VRP Network BL); Gaurav agrawal; VinodS Kumar
Cc: [e-mail]
Subject: [sfc] Few Querries from draft-agv-sfc-packet-delay-measurement-00
 
Hi Anil Kumar S N, Gaurav Agrawal,Vinod Kumar S,I have few question with respect to the delay calculation method described in the draft "draft-agv-sfc-packet-delay-measurement-00".Please let me know your opinion on this queries.1) -------------------------draft section---------------------------------------   3.6 Incoming Packets Processing at MA      On receiving the packet with NSH header following operations are       carried out:      Step 1: Detection of PM Context Header in a packet, by verifying               the PM TLV Class as allocated by IANA.              (If not detected, move to step 6)       Step 2: Check if PM Type field value is 6 to 10.               (If not move to step 6).      Step 3: If PM Type Value = 7 to 10 move directly to Step 5      Step 4: Check Presence of self Service index in Service Index List              (If not present, move to step 6)---------------------------------------------------------------------------MA can be SF or SFF , but based on the steps given here, SFF cannot do the time recording or report to collector becausestep 4 checks the SI index and SFF we do not have Si index.[ SI: List of participating Service functions in the SFP. It SHOULD be    in decreasing order of the SI for optimized traversal of the SI    participation. ]So i thing we need to address SFF scenario as well.[Gaurav-1] Initially we thought of handling SFF during hop by hop measurement scenario only. But we see a valid point here from you, in the new revision ofdraft we are planning to introduce MA identifier which will be combination of node identifier (unique number configured by controller) and order identifier (SI) to address performance measurement of SFF in all scenarios. 
   [NOBIN-1]   Unique number for SFF is assigned per Flow or its global ? if its global then how you will track different paths ? I think you may need to include the Path/flow identifier along with other two identifiers given here. 
                     Do you have plan to assign a unique number for each SF in a service path ? If you do not do this , then i think the context header structure will be different for SF and SFF, please clarify.
 
[Gaurav-2] Unique number for SFF will be global and yes you are right flow identifier (PMF id) is used together for identification
For Example: Please refer section 3.2 in packet delay measurement draft
   1) Rx-Time[P][M][W]
   2) Tx-Time[P][M][W]
 
For SF identification, SFC already incorporates a mechanism of Service Index and we re-use the same. Unification of context header is taken care of, kindly refer section 2.2 of packet delay draft
   MA identifier has two parts</spa

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