Technical Summary
A Virtual Private Wire Service (VPWS) provides a point-to-point
connection service between a pair of Customer Edge (CE) devices
over an IP/MPLS packet switched network using Pseudowire
Emulation Edge to Edge (PWE3) technology. It does so by
binding two Attachment Circuits (ACs), each connecting a CE
device with a Provider Edge (PE) device, to a Pseudowire (PW)
extended between the two PEs. PWE3 defines PW types
that interconnect ACs of the same technology (homogeneous ACs),
e.g., both ACs being Ethernet. In general, a VPWS provides
connectivity between homogeneous ACs using the existing
PWE3 technology. However, if the ACs are layer2 attachment
circuits of heterogeneous types (e.g., one AC is Ethernet and
the other one is a Fame Relay DLCI), and solely carry IP
datagrams in the corresponding packet data units' payload,
it is possible to provide a VPWS that interconnects these
ACs using IP Layer2 Transport PWs often referred to simply
as IP PWs. This requires the PEs to perform a function known
as "ARP Mediation". ARP Mediation refers to the process of
resolving IP addresses to Layer 2 addresses when different
address resolution protocols are used on either Attachment
Circuit. The methods described in this document are applicable
even when the CEs run a routing protocol between them
as long as the routing protocol runs over IP.
Working Group Summary
This document has been in existence since the very beginning
of the PPVPN and L2VPN WG's. At first, it only included
support for IPv4, but subsequently was updated to include
support for IPv6. Ultimately, this document provides a means
of interworking IPv4-enabled ACs, IPv6-enabled ACs and
dual-stack IPv4/IPv6-enabled ACs whereby the ACs are of
disparate Layer2 technologies.
Document Quality
There are no concerns about document quality.
Several implementations of this draft have existed in
the field for several years.
Personnel
Nabil Bitar (nabil.n.bitar@verizon.com) is the Document Shepherd.
Stewart Bryant (stbryant@cisco.com) is the Responsible
Area Director.
RFC Editor Note
In section 2
OLD
A PE that is to perform ARP Mediation for IPv6 packets SHOULD
perform the following logical steps:
NEW
A PE that is to perform ARP Mediation for IPv6 packets MUST
perform the following logical steps:
END
=====
In section 4.3.3 - two places
- end of list item 2
- end of first sentence list item 3
In section 4.3.4 second para
OLD
link-layer address of the local AC
NEW
link layer address of the PE interface attached to local AC
END