Issue No.03 - May/June (2004 vol.8)
Chris Metz , Cisco
In part I of this series, we defined a virtual private network (VPN) as a discrete network entity configured and operated over a public or private shared network infrastructure. We now turn our attention to an equally important type of VPN that is generating much interest and activity in the industry. A Layer-2 VPN (L2VPN) is defined as a VPN that transports native L2 frames across a shared IP or MPLS packet switch network (PSN). The L2 frames can be frame relay protocol data units, ATM cells, or even Ethernet frames and are carried across the PSN using one of several different tunnel encapsulation schemes.
virtual private networks, WAN infrastructures
Chris Metz, "The Latest in VPNs: Part II", IEEE Internet Computing, vol.8, no. 3, pp. 60-65, May/June 2004, doi:10.1109/MIC.2004.1297275