Re: [DMM] Tsvart last call review of draft-ietf-dmm-distributed-mobility-anchoring-13

[CARLOS JESUS BERNARDOS CANO <[e-mail]>]

Dear Yoshifumi,

Thanks a lot for the review. Please check inline below for some comments
from my side.

On Mon, Oct 14, 2019 at 9:57 AM Yoshifumi Nishida via Datatracker <
[e-mail]> wrote:

> Reviewer: Yoshifumi Nishida
> Review result: Almost Ready
>
> This document has been reviewed as part of the transport area review team's
> ongoing effort to review key IETF documents. These comments were written
> primarily for the transport area directors, but are copied to the
> document's
> authors and WG to allow them to address any issues raised and also to the
> IETF
> discussion list for information.
>
> When done at the time of IETF Last Call, the authors should consider this
> review as part of the last-call comments they receive. Please always CC
> [e-mail] if you reply to or forward this review.
>
> Summary: This document is almost ready for publication as an informational
> RFC,
> but it will be better to clarify the following points.
>
> 1: The examples shown in the draft look behave conveniently.
>    For examples, in the figure 3 case, the flow is somehow terminated
> before
>    the MN moves and is re-initiated after the movement has finished.
> However, I
>    believe there should be the cases where applications don't aware of
> network
>    changes and transmit data while migrating, which may cause packet drops,
>    delays and timeouts, etc. I think this draft should clarify the
> treatments
>    of these cases. Is it out of scope of the draft? Or, do some components
>    generate ICMP messages to give some hints to the applications, or
> provide
>    buffering features to mitigate the side effects?
>

[Carlos] I guess you mean Figure 4, right? In that figure, we try to
explain what would happen if there is no actual mobility support, meaning
that a communication flow does not need such mobility support. This might
happen because the flow stops before the movement (as shown in the figure)
or also because the application can deal with the mobility itself (no
mobility at the IP layer). We don't explicitly mention that second case
because it is not in the scope of the draft (IP mobility). We can better
clarify the scope in the text.


>
> 2: Page 8:
>    "A MN will need to choose which IP prefix/address to use for each flow
>     according to whether it needs IP mobility support or not."
>
>      -> It seems to me that the draft implicitly suggests the use of
>      draft-ietf-dmm-ondemand-mobility here.
>         If so, I think it would be better to state more explicitly. Or, do
> we
>         have other options?
>

[Carlos] We can definitely add an explicit reference to
draft-ietf-dmm-ondemand-mobility, but I'd mention it as an example. I don't
have another option in mind, but we can leave it open.


> 3: Page 10:
>     "the initial anchor remains the anchor and forwards traffic"
>
>      -> could be "anchor remains and the anchor.."?
>

[Carlos] Maybe "mobility anchor remains playing that role and forwards
traffic"?

Thanks!

Carlos

>
> Thanks,
> --
> Yoshi
>
>

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