Subject: Re: [mpls-tp] Verizon's comments on draft-ietf-mpls-tp-requirements-04

From: Ben Niven-Jenkins <[email-masked]>
Date: Sun, 08 Mar 2009 23:12:39 +0000

Andy,

Thanks for the comments, See inline, unless otherwise stated I have
incorporated your proposed changes.

On 27/02/2009 19:35, "Andrew G. Malis" <[email-masked]> wrote:
> 14. We found that requirement 14 contains several different
> requirements combined together, and thought it would be more clear to
> break these into separate requirements. While we numbered these 14A,
> B, and C, we don't care if this numbering is used, or if separate
> numbers are used:

OK.

> 14A. The MPLS-TP data plane MUST be capable of forwarding data
> independent of the control or management plane used to configure and
> operate the MPLS-TP layer network. If the control plane fails and does
> not restart, the data plane connections MUST be held and MUST NOT time
> out.
> 
> 14B. The MPLS-TP data plane MUST be capable of taking recovery actions
> independent of the control plane (if any) used to configure and
> operate the MPLS-TP layer network.
> 
> 14C.  If a control plane is used for MPLS-TP, the control plane's
> graceful restart capabilities, if any, MUST be supported.
> 
> (Note that 14C is a new requirement, and came up during our discussion
> of control plane restarting. It may be better placed in section 2.4,
> and that's fine.)

I have placed in section 2.4. BTW the text for 14C above differs from that
in the Word document but I have used the text above as I think it is more
appropriate.

> 16. We would like to add a new second sentence to this requirement. It
> will now read:
> 
> 16  MPLS-TP MUST support transport paths through multiple homogeneous
> domains. MPLS-TP SHOULD support transport paths through multiple
> non-homogeneous domains.
> 
> (We expect this to be a case that will need to be supported.)

OK. I have put as separate requirement.

Ben

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From: "Andrew G. Malis" <[email-masked]>
Date: Sun, 8 Mar 2009 21:49:39 -0400

Ben,

Thanks, much appreciated,

Cheers,
Andy

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From: Greg Mirsky <[email-masked]>
Date: Mon, 9 Mar 2009 15:32:35 -0500

Dear Andy, Ben and All,
I have a question regarding homogeneity of domains crossed by an MPLS-TP
path. I understand such homogeneity as existence of a sufficient number of
MPLS-TP segments to construct an MPLS-TP path through the domain (or from/to
MPLS-TP end-point). But what would "non-homogeneous domain" would be for the
MPLS-TP path?

Regards,
Greg

[snip]
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From: "Andrew G. Malis" <[email-masked]>
Date: Mon, 9 Mar 2009 16:42:43 -0400

Greg,

That would be a multidomain MPLS-TP LSP where some of the domains use
a dynamic control plane and other domains use static provisioning. In
use, we expect to see the case where you want (for example) a
multi-provider LSP where one uses dynamic signaling and the other
doesn't.

Cheers,
Andy

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From: Greg Mirsky <[email-masked]>
Date: Mon, 9 Mar 2009 15:53:58 -0500

Andy,
thank you for the clarification.
But I think that in this case, the requirement is applicable to the Control
Plane and/or Management Plane for the MPLS-TP only (as requirement for
interworking of the two), not the MPLS-TP as a whole. The DP, the MPLS-TP as
a transport network, should not be affected or changed by how an MPLS-TP
path provisioned in any given domain. Or am I seeing it wrong?

Regards,
Greg

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From: "Andrew G. Malis" <[email-masked]>
Date: Mon, 9 Mar 2009 16:59:45 -0400

Greg,

That's correct, but it feels like an "overall" requirement to me since
it affects both the management and control planes.

Cheers,
Andy