Re: [ippm] draft-ietf-ippm-ioam-data and a new draft for IOAM flags

[Tianran Zhou <[e-mail]>]

Hi Frank,

Here are some comments on the IOAM flags:

1. Why proposing the "Immediate Exporting" when a new postcard option (https://datatracker.ietf.org/doc/draft-song-ippm-postcard-based-telemetry/) is already proposed for IOAM? What's the difference for use?
One scenario may apply to this flag is to indicate the node to export all the existing tracing data when the node is not able to attach data. Other capable nodes will still trace and attach data. This may make the flag useful and different.

In addition, you mentioned to use the e2e option to assist the postcard. That may need an encapsulation extension to IPv6 HbH for e2e option.

2. I suggested before. I would like to propose a "significant data" bit in the flag. It is set by the intermediate node who think the attached data is significant. The use case is to reduce the exporting data at the end of the IOAM domain. i.e., only the meta data with "significant data" bit set will be exported. For example, when we are tracing the transit delay hop by hop, transit delay within a threshold may not be useful, and not worth to be exported to the collector. Any intermediate node can set this "significant data" bit when the transit delay breaches the threshold. So data are exported only when path congestion. This can be extended to other examples, e.g. buffer.

Regards,
Tianran

From: ippm [mailto:[e-mail]] On Behalf Of Frank Brockners (fbrockne)
Sent: Friday, July 05, 2019 2:22 AM
To: [e-mail]
Subject: [ippm] draft-ietf-ippm-ioam-data and a new draft for IOAM flags

Back in the IPPM WG meeting in Prague, Tommy concluded on the discussion of draft-ietf-ippm-ioam-data-05, that we should "separate the flag discussion into separate drafts and  then fold it into the data draft based on WG consensus." (see IPPM minutes
https://datatracker.ietf.org/meeting/104/materials/minutes-104-ippm-00). Unfortunately it took a bit longer than expected but today two new documents were published following Tommy's conclusion:

https://tools.ietf.org/html/draft-mizrahi-ippm-ioam-flags-00
https://tools.ietf.org/html/draft-ietf-ippm-ioam-data-06

draft-mizrahi-ippm-ioam-flags-00 is a new document which provides the description of those flags that describe IOAM behavior not immediately associated to updating the IOAM data fields, i.e. the new draft took the text related to flags from the draft-ietf-ippm-ioam-data. draft-ietf-ippm-ioam-data-06 is the associated update to the -05 version with the description of the flags removed.

With the -00 draft cut off still a few days away, it would be great to get comments on the split and even more so on the new ioam-flags draft, so that we could create a rev before the cut off (if required) and then try to close the discussion in Montreal.

Thanks much, Frank