Re: [ippm] 答复: WGLC for STAMP Extensions

Hi Yuezhong,
thank you for your comments and suggestions. Please find my notes and
answers in-line under the GIM>> tag.

Regards,
Greg

On Sat, May 30, 2020 at 4:56 AM Songyuezhong (songyuezhong, IP technology
Research Dept) <songyuezhong@huawei.com> wrote:

> Hi Ian，
>
>
>
> I have read the latest version of this draft，and have some small
> suggestions, hope it is helpful for you.
>
>
>
> For part 4,there list 8 new TLVs, but it seems not detailed enough for
> each TLV about the application scenario and some terms in it, we need guess
> to understand the whole plan.
>
GIM>> We have tried to provide a clear technical description of extensions
to help implementers produce interoperable implementations. Describing
various scenarios an extension may be used in was not our main objective.
There are other SDOs that reference STAMP and STAMP TLVs in their
documents. I can mention BBF's WT-390.2 IP Performance Measurement from IP
Edge to Customer Equipment using STAMP, and MEF's MEF-w66 Service OAM for
IP Services. Both documents are in advanced phase and will be published
later this year.

>
>
> Especially for the people who have no background knowledge of each
> application scenario, maybe it is more hard for them to understand.
>
GIM>> Yes, you are correct. Standard documents require a certain level of
knowledge in the particular area of the technology.

>
>
> So I suggest for each TLV, there should have some pictures and background
> content to help people understand the TLV’s meaning and using method，it
> will be better.
>
GIM>> That is very helpful suggestion and I think that it can be a basis
for the Applicability of STAMP document. Would you be interested in working
on the new document together?

>
>
> By the way, I have some doubt about the Location TLV, which is the last-hop router, the reflector or the router before it? And how to indicate if the STAMP packets are send to the wrong Session-Reflector from this TLV?
>
> GIM>> I hope that Henrik's response clarified one of the use case
scenarios.

>
>
> And another question is how to use Class of Service TLV to find the misconfigure problem, is it enough?
>
> GIM>> One of the possible scenarios could be as follows:

   - STAMP Sender sets DSCP1 to value A
   - STAMP packet is transmitted with DSCP set to A
   - STAMP Reflector copies DSCP value into DSCP2 field
   - reflected STAMP packet is transmitted with DSCP set to A (as requested
   by the STAMP Sender)
   - STAMP Sender receives the STAMP packet with DSCP A but DSCP2 value is
   B not as expected.

I hope this little example helps. Obviously, there are many ways to use the
CoS TLV to test CoS mappings.

>
>
> Thanks,
> Yuezhong
>
>
>
> *发件人:* ippm [mailto:ippm-bounces@ietf.org] *代表 *Ian Swett
> *发送时间:* 2020年5月23日 5:26
> *收件人:* IETF IPPM WG (ippm@ietf.org) <ippm@ietf.org>
> *主题:* [ippm] WGLC for STAMP Extensions
>
>
>
> Hi IPPM,
>
> At our virtual interim meeting, we decided
> draft-ietf-ippm-stamp-option-tlv was ready for last call. This email starts
> a two-week WGLC for this draft.
>
> The latest version can be found here:
> https://tools.ietf.org/html/draft-ietf-ippm-stamp-option-tlv-04
>
> This last call will end on *Monday, June 8th*. Please reply to
> ippm@ietf.org with your reviews and comments.
>
> Thanks,
> Ian & Tommy
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