I have reviewed this document as part of the Operational directorate's ongoing
effort to review all IETF documents being processed by the IESG.  These
comments were written with the intent of improving the operational aspects of
the IETF drafts. Comments that are not addressed in last call may be included
in AD reviews during the IESG review.  Document editors and WG chairs should
treat these comments just like any other last call comments.

Summary:
   This document introduces an optional Availability TLV in
   Resource ReSerVation Protocol - Traffic Engineer (RSVP-TE)
   signaling. This extension can be used to set up a Generalized Multi-
   Protocol Label Switching (GMPLS) Label Switched Path (LSP) in
   conjunction with the Ethernet SENDER_TSPEC object. 
   The term availability is used to describe links with variable bandwidth.

This TLV and its processing described in the document is useful in efficient network planning of the link capacity by communicating different bandwidth availability classes needed by different types of services over variable bandwidth links.
I do not see any operational or manageability related issues due to introducing this new TLV and its processing.

However I concur with the Genart review comment that raises an issue on the recommended behavior of existing implementation of RSVP protocol that do not understand the TLV: https://mailarchive.ietf.org/arch/msg/gen-art/eW3cbYTHCn4G-kwRb3Tqvy2SAV4
This needs to be resolved before the document can be considered ready.