@misc{rfc7274, series = {Request for Comments}, number = 7274, howpublished = {RFC 7274}, publisher = {RFC Editor}, doi = {10.17487/RFC7274}, url = {https://www.rfc-editor.org/info/rfc7274}, author = {Kireeti Kompella and Loa Andersson and Adrian Farrel}, title = {{Allocating and Retiring Special-Purpose MPLS Labels}}, pagetotal = 11, year = 2014, month = jun, abstract = {Some MPLS labels have been allocated for specific purposes. A block of labels (0-15) has been set aside to this end; these labels are commonly called "reserved labels". They will be called "special-purpose labels" in this document. As there are only 16 of these special-purpose labels, caution is needed in the allocation of new special-purpose labels; yet, at the same time, forward progress should be allowed when one is called for. This memo defines new procedures for the allocation and retirement of special-purpose labels, as well as a method to extend the special-purpose label space and a description of how to handle extended special-purpose labels in the data plane. Finally, this memo renames the IANA registry for special-purpose labels to "Special-Purpose MPLS Label Values" and creates a new registry called the "Extended Special-Purpose MPLS Label Values" registry. This document updates a number of previous RFCs that use the term "reserved label". Specifically, this document updates RFCs 3032, 3038, 3209, 3811, 4182, 4928, 5331, 5586, 5921, 5960, 6391, 6478, and 6790.}, }