This document explains what is meant by the term "network transport
Circuit Breaker" (CB). It describes the need for circuit breakers
when using network tunnels, and other non-congestion controlled
applications. It also defines requirements for building a circuit
breaker and the expected outcomes of using a circuit breaker within
The WG has requested Best Current Practice status because this draft
provides protocol design (and in some cases, operational) guidelines
for the Internet. This request is the rough consensus of the WG.
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 strongly supported by the portion of the TSVWG that is
concerned with congestion, and has received reviews and discussions from
several experts within that community. Overall support for this draft
comes from about a dozen members of the WG, which is relatively broad
support for a TSVWG draft. Discussion in TSVWG has not been controversial;
the draft has evolved moderately from the initial -00 version that the
WG adopted about a year ago, with no major objections to its content in
In contrast, the circuit breaker concept has been controversial in other
IETF forums, with strong opposition observed to imposing circuit breaker
support as a protocol design requirement. The concept of a managed
circuit breaker is intended to allow response via a different control-plane
protocol or via other mechanisms such as OAM and/or network operator
monitoring of service delivery. The shepherd expects this issue to
resurface at IETF Last Call, and is accordingly dusting off his (virtual)
There is complementary work elsewhere in the IETF, e.g., the RTP circuit
breaker activity in the AVTCORE WG.
This is a BCP, so not a candidate for direct implementation.
In addition to other reviews from Roni Even and Linda Dunbar,
we received especially detailed reviews from Benjamin Kaduk (for SECDIR)
and Andy Malis (for the RTG directorate).
Document Shepherd: David Black
Responsible AD: Spencer Dawkins