Re: [mpls] New Version Notification for draft-mirsky-spring-bfd-00.txt

Robert Raszuk <robert@raszuk.net> Wed, 10 May 2017 19:40 UTC

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From: Robert Raszuk <robert@raszuk.net>
Date: Wed, 10 May 2017 21:40:00 +0200
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To: "Carlos Pignataro (cpignata)" <cpignata@cisco.com>
Cc: Greg Mirsky <gregimirsky@gmail.com>, "mpls@ietf.org" <mpls@ietf.org>, "spring@ietf.org" <spring@ietf.org>, "rtg-bfd@ietf.org" <rtg-bfd@ietf.org>
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Subject: Re: [mpls] New Version Notification for draft-mirsky-spring-bfd-00.txt
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Hi Carlos,

Sorry what is "TFS" ?

RFC 7110 does not even use such abbreviation neither do
draft-ietf-mpls-bfd-directed :) Google also seems to be pretty clueless
about it.

Just curious as you keep using this term in each email :)

Thx,
R.

On Wed, May 10, 2017 at 9:24 PM, Carlos Pignataro (cpignata) <
cpignata@cisco.com> wrote:

> Greg,
>
> In the MPLS data plane, FECs are also instantiated through a label stack.
> But RFC 7110 does not use numeric label values, it uses TFSs. That does not
> create any additional state. E.g.,: https://www.ietf.org/
> mail-archive/web/mpls/current/msg16091.html
>
> Thanks,
>
> — Carlos.
>
>
>
> On May 9, 2017, at 3:43 PM, Greg Mirsky <gregimirsky@gmail.com> wrote:
>
> Hi Carlos,
> I probably would characterize anything that starts with Why not as a
> technical comment but rather as a question.
> According to draft-ietf-spring-segment-routing-mpls, "In the MPLS
> dataplane,the SR header is instantiated through a label stack".
> At the same time, one of advantages of SR is that "per-flow state only
> [maintained] at the ingress node to the SR domain".
> Thus, for the case of monitoring unidirectional SR tunnels, I consider
> that there's no need to create any additional state on the egress node.
> Of course, if there were bidirectional SR tunnels, then control of the
> reverse direction of the BFD session would not require use of the Return
> Path sub-TLV.
> As for LSP-Ping, I just propose that the Segment Routing MPLS Tunnel
> sub-TLV MAY be used Reply Path TLV defined in RFC 7110. I viewed the
> proposal as invitation to technical discussion.
>
> Regards,
> Greg
>
> On Tue, May 9, 2017 at 9:07 AM, Carlos Pignataro (cpignata) <
> cpignata@cisco.com> wrote:
>
>> Thank you Greg!
>>
>> Since https://tools.ietf.org/html/draft-mirsky-spring-bfd-00 seems quite
>> similar to the text removed at https://tools.ietf.org/rfcdiff
>> ?url2=draft-ietf-mpls-bfd-directed-05.txt, then the complete set of
>> outstanding technical comments that triggered the removal of that text from
>> draft-ietf-mpls-bfd-directed-05.txt might peek your interest :-)
>>
>> One that I recall is: why use label values when every other return-path
>> sub-TLV for BFD and for LSP-Ping, including draft-ietf-mpls-bfd-directed,
>> uses TFSs?
>>
>> Best,
>>
>> — Carlos.
>>
>> On May 9, 2017, at 12:00 PM, Greg Mirsky <gregimirsky@gmail.com> wrote:
>>
>> Dear Carlos,
>> I've decided to re-start the discussion and am interested to hear
>> technical comments to the proposed solution.
>>
>> Regards,
>> Greg
>>
>> On Tue, May 9, 2017 at 8:51 AM, Carlos Pignataro (cpignata) <
>> cpignata@cisco.com> wrote:
>>
>>> Dear Greg,
>>>
>>> Cursorily scanning through this, it seems that most concerns raised and
>>> comments made about the SR sections of draft-ietf-mpls-bfd-directed-0N
>>> (with N < 5) apply to your new draft.
>>>
>>> This is one of those: https://www.ietf.org/ma
>>> il-archive/web/mpls/current/msg15860.html — the list archive shows a
>>> few more. The copy/paste did not address the comments.
>>>
>>> Best,
>>>
>>> — Carlos.
>>>
>>> On May 8, 2017, at 11:33 PM, Greg Mirsky <gregimirsky@gmail.com> wrote:
>>>
>>> Dear All,
>>> perhaps this new draft may is of interest to you.
>>> Your comments, suggestions are most welcome and greatly appreciated.
>>>
>>> Regards,
>>> Greg
>>>
>>> ---------- Forwarded message ----------
>>> From: <internet-drafts@ietf.org>
>>> Date: Mon, May 8, 2017 at 8:29 PM
>>> Subject: New Version Notification for draft-mirsky-spring-bfd-00.txt
>>> To: Gregory Mirsky <gregimirsky@gmail.com>
>>>
>>>
>>>
>>> A new version of I-D, draft-mirsky-spring-bfd-00.txt
>>> has been successfully submitted by Greg Mirsky and posted to the
>>> IETF repository.
>>>
>>> Name:           draft-mirsky-spring-bfd
>>> Revision:       00
>>> Title:          Bidirectional Forwarding Detection (BFD) in Segment
>>> Routing Networks Using MPLS Dataplane
>>> Document date:  2017-05-08
>>> Group:          Individual Submission
>>> Pages:          7
>>> URL:            https://www.ietf.org/internet-
>>> drafts/draft-mirsky-spring-bfd-00.txt
>>> Status:         https://datatracker.ietf.org/
>>> doc/draft-mirsky-spring-bfd/
>>> Htmlized:       https://tools.ietf.org/html/draft-mirsky-spring-bfd-00
>>> Htmlized:       https://datatracker.ietf.org/
>>> doc/html/draft-mirsky-spring-bfd-00
>>>
>>>
>>> Abstract:
>>>    Segment Routing architecture leverages the paradigm of source
>>>    routing.  It can be realized in the Multiprotocol Label Switching
>>>    (MPLS) network without any change to the data plane.  A segment is
>>>    encoded as an MPLS label and an ordered list of segments is encoded
>>>    as a stack of labels.  Bidirectional Forwarding Detection (BFD) is
>>>    expected to monitor any kind of paths between systems.  This document
>>>    defines how to use Label Switched Path Ping to bootstrap and control
>>>    path in reverse direction of a BFD session on the Segment Routing
>>>    network over MPLS dataplane.
>>>
>>>
>>>
>>>
>>> Please note that it may take a couple of minutes from the time of
>>> submission
>>> until the htmlized version and diff are available at tools.ietf.org.
>>>
>>> The IETF Secretariat
>>>
>>>
>>> _______________________________________________
>>> mpls mailing list
>>> mpls@ietf.org
>>> https://www.ietf.org/mailman/listinfo/mpls
>>>
>>>
>>>
>>
>>
>
>