The IESG has approved the following document: - 'GRE-in-UDP Encapsulation' (draft-ietf-tsvwg-gre-in-udp-encap-19.txt) as Proposed Standard This document is the product of the Transport Area Working Group. The IESG contact persons are Mirja Kühlewind and Spencer Dawkins. A URL of this Internet Draft is: https://datatracker.ietf.org/doc/draft-ietf-tsvwg-gre-in-udp-encap/ Technical Summary This document specifies a method of encapsulating network protocol packet within GRE and UDP headers. This GRE-in-UDP encapsulation allows the UDP source port field to be used as an entropy field. This may be used for load balancing of GRE traffic in transit networks using existing ECMP mechanisms. This document also specifies GRE-in-UDP tunnel requirements for two applicability scenarios: (1) general Internet; (2) a traffic-managed controlled environment. The controlled environment has less restrictive requirements than the general Internet. This draft requires the GRE and UDP tunnel endpoints to coincide (both the GRE and UDP headers have to be applied and removed as a pair). This draft does not cover scenarios where arriving GRE traffic is UDP-encapsulated and/or GRE traffic is forwarded after UDP decapsulation. The WG has requested Proposed Standard status because this draft specifies a protocol that is intended for use in the Internet. Working Group Summary The Transport Area WG (TSVWG) is a collection of people with varied interests that don't individually justify their own working groups. This draft is supported by the portion of the tsvwg working group that is familiar with and interested in UDP encapsulation. The draft has received significant review and critique from a number of Transport experts, including the draft shepherd, and has undergone significant modification as a result. These reviews and related work on this draft have resultings in several changes to the UDP guidelines draft (also in TSVWG - rfc5405bis) - this GRE/UDP draft is now aligned with that UDP guidelines draft. This GRE/UDP draft has had a long history - it originally replaced an earlier draft that proposed encapsulation of arbitrary protocols in UDP without a shim header (draft-yong-tsvwg-udp-encap-4-ip-tunneling). This replacement focused initial work on a single encapsulated protocol, GRE. The resulting draft then got caught up in the UDP encapsulation adventure set off by the initial (failed) IETF Last Call on the MPLS/UDP draft. A design team was formed to work out the Transport issues affecting both drafts, primarily requirements for omission of UDP checksums for IPv6 (these cannot be simply stated by reference to RFCs 6935 sand 6936, because some of the requirements apply to protocol design) and congestion control (MPLS/UDP turned out to only be deployable by network operators, and hence can rely to a large extent on network operator provisioning and traffic management). The design team's work on these two problems (and some additional concerns) lead to the publication of the MPLS/UDP draft as RFC 7510 in April 2015, with the expectation that RFC publication of the GRE/UDP draft would follow shortly thereafter. Unfortunately, that didn't happen - the underlying cause is that it was not feasible to specify a single set of requirements that cover both network operator usage of GRE/UDP (Controlled Environment) and general Internet usage (the latter does not apply to MPLS/UDP). The GRE/UDP draft was revised to specify requirements for both applicability scenarios. Multiple reviews by Transport experts have been performed on this draft subsequent to that revision, revision was done, and the shepherd believes that the draft is now (finally) ready for RFC Publication. Document Quality Versions of this specification have been reported for both BSD and Linux, although they may not be current with the revision being forwarded for publication yet. The document shepherd and authors reported that Gorry Fairhurst and Jouni Korhonen both provided reviews with significant impact on the specification. The working group solicited reviews from Donald Eastlake III and Eliot Lear late in the process, and these reviews did not identify significant new issues. Personnel Document Shepherd: David Black Responsible AD: Spencer Dawkins
