TECHNOLOGY

Pseudowire

ARP Mediation

To support service-interworking among TCP/IP and the various Layer 2 technologies that are operating in Pseudowire environments, the HSX 6000 supports an address resolution protocol (ARP) technique called ARP mediation. The HSX 6000 also supports inv-ARP from FR/ATM endpoints and ARP from Ethernet service end points.

The ARP mediation feature provides support for IP encapsulated Pseudowire circuits, allowing point-to-point connections between pairs of remote CE devices. At the data plane, the IP traffic is interworked from a CE Layer 2 format (such as FR, ATM, or Ethernet) to an IP PWE3 encapsulated format, for transport over the MPLS core. The IP PWE3 circuits are an enhancement over Layer 2 encapsulated PWs because they do not carry the Layer 2 header through the MPLS core as part of each data packet. In addition, the IP Pseudowires implicitly allow interworking between CE devices using different Layer 2 encapsulation.