VPN Terminology Flashcards
L3VPN - Layer 3 VPN
Layer 3 VPN (L3VPN)
An L3VPN interconnects sets of hosts and routers based on Layer 3 adresses
L2VPN - Layer 2 VPN
Layer 2 VPN (L2VPN)
Three main types of L2VPNs:
Virtual Private Wire Service (VPWS);
Virtual Private LAN Service (VPLS);
IP-only LAN-like Service (IPLS)
VPLS - Virtual Private LAN Service
Virtual Private LAN Service
A VPLS is a provider service that emulates the full functionality of a traditional Local Area Network (LAN). A VPLS makes it possible to interconnect several LAN segments over a packet switched network (PSN) and makes the remote LAN segments behave as one single LAN.
In a VPLS, the provider network emulates a learning bridge, and forwarding decisions are taken based on MAC addresses or MAC addresses and VLAN tag.
TLS (Transparent LAN Service) was an early name used to describe the VPLS service. TLS has been replaced by VPLS, which is the current term.
The term VPSN (Virtual Private Switched Network) has been replaced by the term VPLS. .
VPWS - Virtual Private Wire Service
Virtual Private Wire Service
A Virtual Private Wire Service (VPWS) is a point-to-point circuit (link) connecting two Customer Edge devices. The link is established as a logical through a packet switched network. The CE in the customer network is connected to a PE in the provider network via an Attachment Circuit; the Attachment Circuit is either a physical or a logical circuit.
The PEs in the core network are connected via a PW. The CE devices can be routers, bridges, switches, or hosts. In some implementations, a set of VPWSs is used to create a multi-site L2VPN network.
A VPWS differs from a VPLS in that the VPLS is point to
multipoint, while the VPWS is point to point.
IPLS - IP-Only LAN-Like Service
An IPLS is very like a VPLS, except that:
o it is assumed that the CE devices are hosts or
routers, not switches,
o it is assumed that the service will only have to carry IP packets, and supporting packets such as ICMP and ARP (otherwise layer 2 packets that do not contain IP are not supported); and
o the assumption that only IP packets are carried by the service
applies equally to IPv4 and IPv6 packets.
While this service is a functional subset of the VPLS service, it is considered separately because it may be possible to provide it by using different mechanisms, which may allow it to run on certain hardware platforms that cannot support the full VPLS functionality.
PW - Pseudo Wire
The PWE3 working group within the IETF specifies the pseudo wire technology. A pseudo wire is an emulated point-to-point connection over a packet switched network that allows the interconnection of two nodes with any L2 technology.
The PW shares some of the building blocks and architecture constructs with the point-to-multipoint solutions; e.g., PE and CE.
VLAN - Virtual LAN
The term VLAN was specified by IEEE 802.1Q; it defines a method of differentiating traffic on a LAN by tagging the Ethernet frames. By extension, VLAN is used to mean the traffic separated by Ethernet frame tagging or similar mechanisms.
VLLS - Virtual Leased Line Service
The term VLLS has been replaced by term VPWS. VLLS was used in a now dated document intended to create metrics by which it should have been possible to compare different L2VPN solutions. This document
has now expired, and the work has been terminated.
VPN - Virtual Private Network
VPN is a generic term that covers the use of public or private networks to create groups of users that are separated from other network users and that may communicate among them as if they were on a private network. It is possible to enhance the level of separation (e.g., by end-to-end encryption), but this is outside the scope of IETF VPN working group charters. This VPN definition is from [RFC2764]
In the [L3VPN-FRAME], the term VPN is used to refer to a specific set of sites as either an intranet or an extranet that have been configured to allow communication. Note that a site is a member of at least one VPN and may be a member of many.
