Re: [mpls] I-D Action: draft-ietf-mpls-rsvp-shared-labels-01.txt

[Alexander Okonnikov <[e-mail]>]

Hi authors,


I sent comments (27.12.2017, cited below) regarding version -00 of the 
draft, but have not received answers. Could you please provide some 
explanations?


"The draft highlights benefits of proposed solution, but doesn't mention 
drawbacks. For example, in case of regular RSVP-TE LSP transit LSRs are 
able to perform conditioning of traffic of individual RSVP-TE LSP, 
thankfully to unique ingress labels of LSPs. I.e. for regular RSVP-TE 
LSPs incoming label is not only key for seeking ILM entry, but 
(optionally) is input for classifier as well.

Also, the draft points, as one of benefits, hitless re-routing nature. 
Regular RSVP-TE LSPs are also could be re-routed in hitless manner. RFC 
3209 says that if two LSPs have the same ERO, common label can be 
assigned for them. So, this benefit is questionable."


As I understand, due to specifics of the solution node protection cannot 
be provided as well, which is one more drawback of the solution.


Thank you in advance.


05.03.2018 18:24, [e-mail] пишет:
> A New Internet-Draft is available from the on-line Internet-Drafts directories.
> This draft is a work item of the Multiprotocol Label Switching WG of the IETF.
>
>          Title           : Signaling RSVP-TE tunnels on a shared MPLS forwarding plane
>          Authors         : Harish Sitaraman
>                            Vishnu Pavan Beeram
>                            Tejal Parikh
>                            Tarek Saad
> 	Filename        : draft-ietf-mpls-rsvp-shared-labels-01.txt
> 	Pages           : 21
> 	Date            : 2018-03-05
>
> Abstract:
>     As the scale of MPLS RSVP-TE networks has grown, so the number of
>     Label Switched Paths (LSPs) supported by individual network elements
>     has increased.  Various implementation recommendations have been
>     proposed to manage the resulting increase in control plane state.
>
>     However, those changes have had no effect on the number of labels
>     that a transit Label Switching Router (LSR) has to support in the
>     forwarding plane.  That number is governed by the number of LSPs
>     transiting or terminated at the LSR and is directly related to the
>     total LSP state in the control plane.
>
>     This document defines a mechanism to prevent the maximum size of the
>     label space limit on an LSR from being a constraint to control plane
>     scaling on that node.  That is, it allows many more LSPs to be
>     supported than there are forwarding plane labels available.
>
>     This work introduces the notion of pre-installed 'per Traffic
>     Engineering (TE) link labels' that can be shared by MPLS RSVP-TE LSPs
>     that traverse these TE links.  This approach significantly reduces
>     the forwarding plane state required to support a large number of
>     LSPs.  This couples the feature benefits of the RSVP-TE control plane
>     with the simplicity of the Segment Routing MPLS forwarding plane.
>
>     This document also introduces the ability to mix different types of
>     label operations along the path of an LSP, thereby allowing the
>     ingress router or an external controller to influence how to
>     optimally place a LSP in the network.
>
>
>
> The IETF datatracker status page for this draft is:
> https://datatracker.ietf.org/doc/draft-ietf-mpls-rsvp-shared-labels/
>
> There are also htmlized versions available at:
> https://tools.ietf.org/html/draft-ietf-mpls-rsvp-shared-labels-01
> https://datatracker.ietf.org/doc/html/draft-ietf-mpls-rsvp-shared-labels-01
>
> A diff from the previous version is available at:
> https://www.ietf.org/rfcdiff?url2=draft-ietf-mpls-rsvp-shared-labels-01
>
>
> 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:
> ftp://ftp.ietf.org/internet-drafts/
>
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