Re: [sfc] I-D Action: draft-ietf-sfc-multi-layer-oam-11.txt

[[e-mail]]

Hi Med,


thank you the expedient response, Please find my follow-up notes in-lined below tagged GIM2>>.








Regards,


Greg Mirsky






Sr. Standardization Expert
预研标准部/有线研究院/有线产品经营部 Standard Preresearch Dept./Wireline Product R&D Institute/Wireline Product Operation Division









E: [e-mail] 
www.zte.com.cn






Original Mail



Sender: [e-mail]
To: gregory mirsky10211915;
CC: [e-mail];[e-mail];
Date: 2021/05/27 23:38
Subject: Re: [sfc] I-D Action: draft-ietf-sfc-multi-layer-oam-11.txt


_______________________________________________
sfc mailing list
[e-mail]
https://www.ietf.org/mailman/listinfo/sfc

 

Hi Greg,


 


Please see inline.


 


Cheers,


Med


 




De : sfc [mailto:[e-mail]] De la part de [e-mail]
 Envoyé : vendredi 28 mai 2021 05:45
 À : BOUCADAIR Mohamed TGI/OLN <[e-mail]>
 Cc : [e-mail]; [e-mail]
 Objet : Re: [sfc] I-D Action: draft-ietf-sfc-multi-layer-oam-11.txt




 

Hi Med,

many thanks for your help improving this document. I greatly appreciate your thoughtful and detailed comments. Please find my notes in-lined below under the GIM>> tag. I've atteched the working version and diff to highlight the proposed updates.

Regards,


Greg Mirsky


Sr. Standardization Expert
 Original Mail








Sender: [e-mail]



To: Greg Mirsky;



CC: [e-mail];



Date: 2021/05/26 00:09



Subject: Re: [sfc] I-D Action: draft-ietf-sfc-multi-layer-oam-11.txt




Hi Greg,  
 
 Thank you for taking care of most of the comments. This version is much better. 

I see that no changes were made to show how the requirements in Section 3 are met with the proposed solution. I'm sure you have good reasons for that. 

GIM>> I just missed it. Would adding the new text below to the first paragraph of Section 5 be acceptable:

NEW TEXT:

  The SFC NSH Echo Request/Reply defined in this document

   addresses several requirements listed in Section 3.  Specifically, as

   defined in this specification, it can be used to check the continuity

   of an SFP, trace an SFP, localize the failure of the SFP.

[Med] Works for me. Thanks. 

Also, I have one clarification question about the following: 



 (1)
    The sender of the Echo Request MAY use TLVs to
    request that the corresponding Echo Reply is transmitted over the

   specified path.

GIM>> I propose adding informational reference to draft-ao-sfc-oam-return-path-specified as follows:

[Med] I would prefer to have the content of ao-sfc-oam-return-path-specified included in draft-ietf-sfc-multi-layer-oam unless you are confident to progress that I-D separately. It is up to you.

GIM2>> Thank you for the suggestion. I see the rationale merging the substantive part of draft-ao-sfc-oam-return-path-specified in ths document. I hope the WG Chairs share their thoughts on the best way forward. I'll split the question into a separate thread.




NEW TEXT:

   [I-D.ao-sfc-oam-return-path-specified] provides an    example of a TLV that can be used to specify the path of the Echo    Reply. 

 (2)
 
    *  Reply via Specified Path (TBA8) value to enforce the use of the
       particular return path specified in the included TLV to verify bi-
       directional continuity and also increase the robustness of the
       monitoring by selecting a more stable path.

I fail to see which TLVs will be used to specify the "return path". Did I missed something? 


 

GIM>> And here also can refer to draft-ao-sfc-oam-return-path-specified as follows:

NEW TEXT:

      [I-D.ao-sfc-oam-return-path-specified] provides an example of

      defining a specific path for the Echo Reply.


[Med]  Apologies for the late comment but when thinking about this part:


   To trace a particular RSP, the sender may use NSH MD Type 2 Flow ID


   TLV [I-D.ietf-sfc-nsh-tlv].  The value of the Flow ID field of the


   SFP Echo Request packet MUST be set to the same value as of the


   monitored flow.


I failed to see how flow-id can be help for tracing (list if SFs that were involve in an SFP). Having a list of IP addresses is not sufficient as we need the identity of the SFs that were involved. The registry in draft-ietf-bess-nsh-bgp-control-plane-18#section-10.5 would be useful for this. If you can clarify that part in the text, that would be great. Thank you. 





 GIM2>> I much appreciate your comments and questions. I agree with you, Flow-id alone would not reflect SFs. I've updated the text adding the reference to draft-ao-sfc-oam-path-consistency. Mechanism described in that draft allows the collection of the SF Type information as specified


in the Service Function Type registry defined in draft-ietf-bess-nsh-bgp-control-plane.


NEW TEXT:

  To trace a particular RSP, the sender may use NSH MD Type 2 Flow ID

   TLV [I-D.ietf-sfc-nsh-tlv] in combination with the method described

   in [I-D.ao-sfc-oam-path-consistency].  The value of the Flow ID field

   of the SFP Echo Request packet MUST be set to the same value as of

   the monitored flow.


In Section 3.3 draft-ao-sfc-oam-path-consistency:

  SF Type: Two octets long field.  It is defined in

   [I-D.ietf-bess-nsh-bgp-control-plane] and indicates the type of SF,

   e.g., Firewall, Deep Packet Inspection, WAN optimization controller,

   etc.


What are your thoughts?




_________________________________________________________________________________________________________________________ Ce message et ses pieces jointes peuvent contenir des informations confidentielles ou privilegiees et ne doivent donc pas etre diffuses, exploites ou copies sans autorisation. Si vous avez recu ce message par erreur, veuillez le signaler a l'expediteur et le detruire ainsi que les pieces jointes. Les messages electroniques etant susceptibles d'alteration, Orange decline toute responsabilite si ce message a ete altere, deforme ou falsifie. Merci. This message and its attachments may contain confidential or privileged information that may be protected by law; they should not be distributed, used or copied without authorisation. If you have received this email in error, please notify the sender and delete this message and its attachments. As emails may be altered, Orange is not liable for messages that have been modified, changed or falsified. Thank you.