Introduction to Virtual Private Wire Services (VPWS)

 Virtual Private Wire Services (VPWS)

I am not sure how many of you heard about VPWS (Virtual private wire service). It is a Layer 2 VPN services over MPLS to build a topology of point-to-point connections between the sites of the customer across (between two CE routers)

In short these VPWS services are actually an alternative to private networks (VPLS) that have been provisioned by means of dedicated lines and generally uses ATM, Frame Relay networks.  

Note⭐: The concept here used is Pseudo-Wire between the PE routers over the MPLS network which enables the Layer 2 traffic over the MPLS. The PE-CE link is referred to as Attachment Circuit (AC)

Fig 1.1- Virtual Private Wire Services (VPWS)

L2 traffic flows over the MPLS as VPWS services
In whole scenario, if we talked about the traffic flow which is l2 traffic, the remote end CE router forwards L2 packet to the remote end PE router and then Remote end PE router pushes VC label to L2 packet received from remote CE router. Remote PE router pushed outer (Tunnel) label and forwards packet to P router (second one).

Second P Router and First P router forward packet using outer label swap. Router Local PE pops Tunnel label and based on VC label, L2 packet is forwarded to customer interface to Local CE router, after VC label is removed.