Re: [Gen-art] Genart telechat review of draft-ietf-lime-yang-connectionless-oam-methods-09

[Brian E Carpenter <[e-mail]>]

Qin,

Thanks for the reply, I have follow-up questions in line:

On 17/10/2017 00:52, Qin Wu wrote:
> Thank Brian for valuable review to this document, please see my reply below.
> 
> -Qin
> -----邮件原件-----
> 发件人: Brian Carpenter [mailto:[e-mail]] 
> 发送时间: 2017年10月14日 12:40
> 收件人: [e-mail]
> 抄送: [e-mail]; [e-mail]
> 主题: Genart telechat review of draft-ietf-lime-yang-connectionless-oam-methods-09
> 
> Reviewer: Brian Carpenter
> Review result: Ready with Issues
> 
> Gen-ART *Last Call* review of draft-ietf-lime-yang-connectionless-oam-methods-09
> 
> I am the assigned Gen-ART reviewer for this draft. The General Area Review Team (Gen-ART) reviews all IETF documents being processed by the IESG for the IETF Chair.  Please treat these comments just like any other last call comments.
> 
> For more information, please see the FAQ at <http://wiki.tools.ietf.org/area/gen/trac/wiki/GenArtfaq>.
> 
> Document: draft-ietf-lime-yang-connectionless-oam-methods-09.txt
> Reviewer: Brian Carpenter
> Review Date: 2017-10-14
> IETF LC End Date: 2017-10-25
> IESG Telechat date: 2017-10-26
> 
> Summary: Ready with issues
> --------
> 
> Comment:
> --------
> 
> The shepherd says:
> 
>> This includes at least two different implementations of the model, as 
>> well as product and demos at Bits-n-Bytes.
> 
> Shouldn't WGs make routine use of BCP 205, RFC 7942 "Improving Awareness of Running Code: The Implementation Status Section"?
> 
> Minor Issues:
> -------------
> 
> In the following:
> 
>          |  +--ro min-delay-value?         uint32
>          |  +--ro max-delay-value?         uint32
>          |  +--ro average-delay-value?     uint32
>          +--ro session-jitter-statistics
>          |  +--ro time-resolution-value?   identityref
>          |  +--ro min-jitter-value?        uint32
>          |  +--ro max-jitter-value?        uint32
>          |  +--ro average-jitter-value?    uint32
> 
> what are the units for the delay-value and jitter-value elements, and what definition of 'jitter' is intended?
> 
> [Qin]: Delay supports various time units such as s,ms,ns and etc.
> To represent this using YANG construct, we introduce a new parameter time-resolution-value as follows:
>    |     +--ro session-delay-statistics
>    |     |  +--ro time-resolution-value?   identityref
>    |     |  +--ro min-delay-value?         uint32
>    |     |  +--ro max-delay-value?         uint32
>    |     |  +--ro average-delay-value?     uint32
> With this time-resolution-value parameter, we can support various different time unit.

OK, because of my poor understanding of YANG, I still have to ask where
the possible values of time-resolution-value are defined. Is there
an enumeration somewhere that I have missed?

> The same is applied to jitter. As clarified in the introduction, the definition of 'jitter' is used to 
> monitor reachability of destinations, troubleshoot failures, monitor performance.

Yes, but what *is* jitter physically? There is no scientific definition of
'jitter' in the IETF. Do you mean IPDV as defined in RFC3393 or something
else?

I assume that by 'delay' you mean RFC7679 rather than RFC2681, but that seems
straightforward,  and so do the other metrics used in session-packet-statistics
and session-error-statistics.

Regards
    Brian

> 
>   identity protocol-id-internet {
>     base protocol-id;
>     description
>       "Internet Protocols.";
>   }
> 
> It isn't clear what "Internet Protocols" means. It seems totally non-specific.
> 
> 
> [Qin]: It is referred to a standard protocol (e.g., TCP/IP protocols, ICMP, IGMP,etc.,)
> We can make this clear by adding a few clarification text in the description of protocol-id-internet.
> Nits:
> -----
> 
>   identity protocol-id-propreitary {
>     base protocol-id;
>     description
>       "Propreitary protocol (eg.,IP SLA).";
> 
> s/propreitary/proprietary/
> s/Propreitary/Proprietary/
> 
> [Qin]: Thanks and will get this fixed.
>