The IETF PWE3 Working Group has defined many encapsulations of
various layer 1 and layer 2 service-specific PDUs and circuit data.
In most of these encapsulations, use of the Pseudowire (PW) Control
Word is required. However, there are several encapsulations for
which the Control Word is optional, and this optionality has been
seen in practice to possibly introduce interoperability concerns
between multiple implementations of those encapsulations. This
survey of the PW/VCCV user community was conducted to determine
implementation trends and the possibility of always mandating the
Working Group Summary
RFC5085 defines 3 VCCV channel types. These are essentially the mechanisms
for transport of the PW associated channel that is used to carry e.g. PW OAM
messages. In addition, RFC6423 adds a 4th mechanism which uses the GAL. There
is currently no clear definition of which modes are mandatory and which modes
are optional to implement. This has caused concerns by some participants in
the operator community that the proliferation of modes causes interoperability
issues between vendors. As a first step to rationalising the number of modes,
the WG conducted a survey to try to quantify which modes are in use today and so
determine which ones could be either deprecated, or made optional in a possible
future update to RFC5085. This draft contains the results of that survey. Since the
survey contains useful information pertaining to the current state of PW deployments,
there was consensus to record the results of the survey in an Informational RFC.
Note that the draft spent an extended amount of time in AD review while additional
editorial help was sought to address the comments from the AD. During this period the
draft went dormant. Additional editorial help was eventually found, and the draft progressed
as it was felt that the survey results contained therein were still relevant. The WG
has also been using these results as a basis for on-going work, and it was felt that a
permanent record of the results is desirable.
Note that the name of the document that was originally last called by the WG was
draft-ietf-pwe3-pw-vccv-impl-survey-results, but this was updated to
draft-ietf-pwe3-vccv-impl-survey-results as a result of a comment from
The document does not specify any MIB changes or additions which would
The document shepherd is Matthew Bocci.
The responsible Area Director is Stewart Bryant.