[mpls] An MPLS Forwarding plane for SFC

"Adrian Farrel" <adrian@olddog.co.uk> Fri, 01 September 2017 20:16 UTC

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From: Adrian Farrel <adrian@olddog.co.uk>
To: mpls@ietf.org
Cc: 'Service Function Chaining IETF list' <sfc@ietf.org>
Date: Fri, 01 Sep 2017 21:15:55 +0100
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Subject: [mpls] An MPLS Forwarding plane for SFC
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We've been working up some ideas for using an MPLS forwarding plane (switching
or SR) for SFC.

We have constrained ourselves to the architecture developed by the SFC working
group, and have used the NSH as a functional model.

MPLS is somewhat limited compared to the NSH encapsulation, so there is a
trade-off between using a new encapsulation with full function and a good set of
function using an existing forwarding plane.

At the moment this is an early version of our work, but we thought you'd like to
see our thought processes.

(FWIW draft-ietf-bess-nsh-bgp-control-plane is applicable to NSH or MPLS
encapsulations and includes mechanisms to select between the two.)


> -----Original Message-----
> From: I-D-Announce [mailto:i-d-announce-bounces@ietf.org] On Behalf Of
> internet-drafts@ietf.org
> Sent: 01 September 2017 21:00
> To: i-d-announce@ietf.org
> Subject: I-D Action: draft-farrel-mpls-sfc-00.txt
> A New Internet-Draft is available from the on-line Internet-Drafts
>         Title           : An MPLS-Based Forwarding Plane for Service Function
>         Authors         : Adrian Farrel
>                           Stewart Bryant
>                           John Drake
> 	Filename        : draft-farrel-mpls-sfc-00.txt
> 	Pages           : 23
> 	Date            : 2017-09-01
> Abstract:
>    Service Function Chaining (SFC) is the process of directing packets
>    through a network so that they can be acted on by an ordered set of
>    abstract service functions before being delivered to the intended
>    destination.  An architecture for SFC is defined in RFC7665.
>    The Network Service Header (NSH) can be inserted into packets to
>    steer them along a specific path to realize a Service Function Chain.
>    Multiprotocol Label Switching (MPLS) is a widely deployed forwarding
>    technology that uses labels to identify the forwarding actions to be
>    taken at each hop through a network.  Segment Routing is a mechanism
>    that provides a source routing paradigm for steering packets in an
>    MPLS network.
>    This document describes how Service Function Chaining can be achieved
>    in an MPLS network by means of a logical representation of the NSH in
>    an MPLS label stack.
> The IETF datatracker status page for this draft is:
> https://datatracker.ietf.org/doc/draft-farrel-mpls-sfc/
> There are also htmlized versions available at:
> https://tools.ietf.org/html/draft-farrel-mpls-sfc-00
> https://datatracker.ietf.org/doc/html/draft-farrel-mpls-sfc-00
> 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.
> Internet-Drafts are also available by anonymous FTP at:
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