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

"Adrian Farrel" <afarrel@juniper.net> Tue, 28 July 2015 18:40 UTC

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From: Adrian Farrel <afarrel@juniper.net>
To: 'Andrew Qu' <andrew.qu@mediatek.com>
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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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Andrew,

> 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.

Adrian