Re: [mpls] draft-fang-mpls-label-forwarding-no-swap - how much does it really save?

"Adrian Farrel" <> Tue, 28 July 2015 18:40 UTC

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From: Adrian Farrel <>
To: 'Andrew Qu' <>
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Date: Tue, 28 Jul 2015 19:36:22 +0100
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Subject: Re: [mpls] draft-fang-mpls-label-forwarding-no-swap - how much does it really save?
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> I just want to have one issue clarified before moving to another.
> Do we agree that _IF_ global label becomes necessary,  no-swap as primitive is
> necessary?

No, not really.
A new primitive may be useful to describe what goes on in such a world, but it
is not necessary because we can already describe such a world.

But, underlying this is the question: what are these primitives? They are not
things you see on the wire; they are descriptions of what goes on inside a
router/switch. They don't need to be defined for standardisation.

The place that all of this might be useful is on an interface that is used to
program a device. If that is useful then go for it - write the data model or
interface spec for it. But I don't believe this has anything to do with 3031.

> Understood that _IF_ will be next topic to follow.

Appreciate separating the two questions although maybe you have the order wrong

Obviously, Stewart's words of warning about integrating with legacy devices
doing downstream label allocation must be considered. but that is a network
design issue.