Virtual network
From Wikipedia, the free encyclopedia
A virtual network provides the virtual links between nodes in a physical computer network to form a virtual network. The implementation of these virtual links may or may not correspond to physical connections between nodes.
The terms VLAN, VPN, and VPLS are all used to describe different types of virtual network.
A VLAN is a partitioning of a network into multiple subnets using a VLAN ID. The partitioned network can be on a single router, can be on multiple routers that would otherwise form a single network, or can be on a VPN.
A VPN is multiple remote routers (or networks) joined by some sort of tunnel over another network, usually a third party network. Two such routers constitute a 'Point to Point Virtual Private Network' (or a PTP VPN). Connecting more than two routers by putting in place a mesh of tunnels creates a 'Multipoint VPN'.
A VPLS is a specific type of Multipoint VPN. VPLS are divided into Transparent LAN Services (TLS) and Ethernet Virtual Connection Services. A TLS sends what it receives, so it provides geographic separation, but not VLAN subnetting. An EVCS adds a VLAN ID, so it provides geographic separation and VLAN subnetting.
