Re: [mpls] Comment on draft-gandhi-mpls-ioam-sr-05

[[e-mail]]

Hi Loa,




Thank you for your comments.
Please see inline my responses with <XM>.




Best Regards,
Xiao Min



原始邮件



发件人：LoaAndersson
收件人：肖敏10093570;[e-mail];
日 期 ：2021年01月17日 13:04
主 题 ：Re: [mpls] Comment on draft-gandhi-mpls-ioam-sr-05


Xiao,
 
imline please.
 
 
On 12/01/2021 09:49, [e-mail] wrote:
> Hi authors,
>  
> While looking through the updated -05 version of this draft, a question  
> emerged in my mind, with the separated Edge-to-Edge IOAM Indicator Label  
> and Hop-by-Hop IOAM Indicator Label,
 
FWIW my take here is that the Edge-to-Edge IOAM only is processed on the  
edge nodes and that Hop-by-Hop IOAM is processed by all nodes on along  
the LSP, including the edge node.
<XM> I absolutely agree.


how can the network operator
> achieve both the Edge-to-Edge IOAM and Hop-by-Hop IOAM simultaneously?
 
If I understand this correctly that is what is done by Hop-by-Hop IOAM.
<XM> Per IOAM itself, the Edge-to-Edge IOAM and Hop-by-Hop IOAM are independent of each other, they use different IOAM Option-Type. Per MPLS indicator label, I agree with you that Hop-by-Hop IOAM indicator label can be reused here, but IMHO the current text in this draft is not clear on it.



> I think there are two ways to achieve that, one way is to define the  
> third IOAM Indicator Label which indicates the existence of both  
> Edge-to-Edge IOAM and Hop-by-Hop IOAM,  
 
I don't see that as necessary, isn't that what the Hop-by-Hop IOAM  
indicator does.
<XM> See above.


another way is to merge the
> current two IOAM Indicator Labels and let the IOAM Option-Type to tell  
> the difference between Edge-to-Edge IOAM and Hop-by-Hop IOAM.
 
Does that mean that even if you are only Edge-to-Edge IOAM  you need to  
inspect the IOAM Option-Type on every node for evey packet?
<XM> Yes, correct. Actually you provide the third way to reuse the Hop-by-Hop IOAM indicator label, for the network operator to achieve both the Edge-to-Edge IOAM and Hop-by-Hop IOAM simultaneously. Acc to the reply from the author, the third way you provide is preferred by the authors, then I suggest to document this way explicitly, in my view this way is not reflected in the current text clearly.


My 2 c's, but I'm willing to be corrected.
 
/Loa
>  
> Best Regards,
> Xiao Min
>  
> 原始邮件
> *发件人：*[e-mail]
> *收件人：*[e-mail] ;
> *抄送人：*[e-mail];
> *日 期 ：*2021年01月09日 23:49
> *主 题 ：**[mpls] I-D Action: draft-gandhi-mpls-ioam-sr-05.txt*
>  
> A New Internet-Draft is available from the on-line Internet-Drafts directories.
> This draft is a work item of the Multiprotocol Label Switching WG of the IETF.
>  
>          Title           : MPLS Data Plane Encapsulation for In-situ OAM Dataloo
>          Authors         : Rakesh Gandhi
>                            Zafar Ali
>                            Clarence Filsfils
>                            Frank Brockners
>                            Bin Wen
>                            Voitek Kozak
>      Filename        : draft-gandhi-mpls-ioam-sr-05.txt
>      Pages           : 14
>      Date            : 2021-01-09
>  
> Abstract:
>     In-situ Operations, Administration, and Maintenance (IOAM) records
>     operational and telemetry information in the data packet while the
>     packet traverses a path between two nodes in the network.  This
>     document defines how IOAM data fields are transported with MPLS data
>     plane encapsulation using new Generic Associated Channel (G-ACh),
>     including Segment Routing (SR) with MPLS data plane (SR-MPLS).
>  
>  
> The IETF datatracker status page for this draft is:
> https://datatracker.ietf.org/doc/draft-gandhi-mpls-ioam-sr/
>  
> There are also htmlized versions available at:
> https://tools.ietf.org/html/draft-gandhi-mpls-ioam-sr-05
> https://datatracker.ietf.org/doc/html/draft-gandhi-mpls-ioam-sr-05
>  
> A diff from the previous version is available at:
> https://www.ietf.org/rfcdiff?url2=draft-gandhi-mpls-ioam-sr-05
>  
>  
> Please note that it may take a couple of minutes from the time of submission
> until the htmlized version and diff are available at tools.ietf.org.
>  
> Internet-Drafts are also available by anonymous FTP at:
> ftp://ftp.ietf.org/internet-drafts/
>  
>  
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--  
 
Loa Andersson                        email: [e-mail]
Senior MPLS Expert                          [e-mail]
Bronze Dragon Consulting             phone: [phone]