Liaison statement
Status of Layer One VPN Work in the IETF

Submission date 2005-11-30
From IETF L1VPN WG (Adrian Farrel)
To ITU-T Study Group 13 (Georges Sebek)
Cc Tomonori Takeda, Hamid Ould-Brahim, Scott Bradner, Alex Zinin, Bill Fenner, L1VPN Working Group
Response contact Adrian Farrel
Technical contact Adrian Farrel, Tomonori Takeda, Hamid Ould-Brahim
Purpose For information
Attachments (None)
The L1VPN Working Group would like to take this opportunity to inform
ITU-T Study Group 13 of its progress on the development of protocol
solutions for Layer One VPNs.

The L1VPN Working Group was chartered in the summer of this year. You
can see the details of the scope of work for the working group at

The working group is discussing two documents:
presents a framework for L1VPNs and draws much of its material from
Recommendations Y.1312 and Y.1313. The purpose of this framework is to
in developing and standardizing protocols and mechanisms to support
interoperable L1VPNs. The document examines motivations for L1VPNs,
high level (service level) requirements, and outlines some of the
models that might be used to build L1VPNs.
provides an applicability analysis on the use of Generalized
Multiprotocol Label Switching (GMPLS) protocols and mechanisms to
satisfy the requirements of Layer 1 Virtual Private Networks (L1VPNs).
In addition, this document identifies areas where additional protocol
extensions or procedures are needed to satisfy the requirements of
L1VPNs, and provides guidelines for potential extensions. The intention
is that, as new protocol extensions are developed to meet the
requirements identified here
and in the framework document, this document will convert to being a
simple applicability statement.

The working group believes that these two documents are largely stable,
and is now working to develop protocol solutions for the "Basic Mode"
L1VPN. This mode of operation involves only signaling protocol
(i.e. no routing) between CE and PE in the network.

Two Internet-Drafts currently exist in support of the protocol
extensions needed for the Basic Mode as identified in the applicability
describes an operational model using either provisioning or a VPN
auto-discovery mechanism and defines signaling extensions for the L1VPN
Basic Mode.
defines a BGP-based auto-discovery mechanism for Layer One VPNs that
allows the provider network devices to dynamically discover the set of
PEs having ports attached to CEs member of the same VPN.

The working group is likely to adopt work items based on these
Internet-Drafts in the near future.

A further work item to provide an OSPF-based auto-discovery mechanism
is being developed but is not available at this time.

Lastly, the working group is now begining to discuss prefered solutions
and models for the "Extended Mode" of L1VPN operation that includes
signaling and routing control.

The L1VPN Working Group would like to encourage the involvement of all
interested parties through the open mailing list. Subscription details
can be found at the charter page

The review and feedback of Study Group 13 on any of this work would
also be most welcome.

Tomonori Takeda
Hamid Ould-Brahim
Adrian Farrel
(L1VPN Working Group co-chairs)