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

Stewart Bryant <stbryant@cisco.com> Mon, 20 July 2015 15:55 UTC

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Date: Mon, 20 Jul 2015 16:55:30 +0100
From: Stewart Bryant <stbryant@cisco.com>
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Subject: [mpls] draft-fang-mpls-label-forwarding-no-swap - how much does it really save?
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I am curious about how much is actually saved with the MPLS dataplane
change proposed in this draft.

If this is used in an Ethernet environment the LSR already needs to
remove and replace the Ethernet header.

In many implementations the datalink header and the MPLS outer
label are part of the same re-write string. So what is the true
gain in writing 14 bytes instead of 18 bytes?

... or is this planned for use with some pt-pt data link other
than Ethernet which is required to be constant end to end?

- Stewart