Re: [Lsr] Prefix Unreachable Announcement Use Cases

Gyan Mishra <hayabusagsm@gmail.com> Tue, 17 November 2020 07:58 UTC

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From: Gyan Mishra <hayabusagsm@gmail.com>
Date: Tue, 17 Nov 2020 02:51:35 -0500
Message-ID: <CABNhwV07Qa-pYON_ajAUsykidnNV8dqTDWWLaJSTiVqLA=ED0w@mail.gmail.com>
To: Tony Li <tony.li@tony.li>
Cc: Aijun Wang <wangaijun@tsinghua.org.cn>, lsr <lsr@ietf.org>, Jeff Tantsura <jefftant.ietf@gmail.com>, Robert Raszuk <robert@raszuk.net>, "Acee Lindem (acee)" <acee=40cisco.com@dmarc.ietf.org>
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Subject: Re: [Lsr] Prefix Unreachable Announcement Use Cases
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Tony

I agree.  We have to be careful not to confuse path protection mentioned to
RSVP FRR protection based on TEDs or LFA style local protection.  We will
redo the verbiage carefully to not call use pre-existing terminology term
that will add confusion.

Thanks for the feedback!!

Thanks

Gyan

On Tue, Nov 17, 2020 at 1:31 AM <tony.li@tony.li> wrote:

>
> And how would that help connectivity restoration ?
> *[WAJ] This action will trigger the path protection procedures, which will
> divert the traffic to other backup path.*
>
>
>
> This seems to be making some major assumptions about how path protection
> features operate. Those assumptions need to be
> very explicitly called out.
>
> The path protection features that I’m familiar with are triggered by
> topological changes along the existing operable path. A PUA
> does not provide that.  Rather, it’s something of a temporary signal
> saying ’this broke’. Without more specifics about the failure, it’s
> difficult to
> understand exactly what path protection should make of this.  If a prefix
> is unreachable, the obvious implication is that the associated link has
> failed.  Path protection in a remote area is highly unlikely to have the
> topological details necessary to find an alternate path to that prefix.
>
> Tony
>
> _______________________________________________
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