Figure: IP interworking VLL (Ipipe) provides an example of IP connectivity between a host attached to a point-to-point access circuit (FR, ATM, PPP) with routed PDU IPv4 encapsulation and a host attached to an Ethernet interface. Both hosts appear to be on the same LAN segment. This feature is supported for the 7450 ESS and 7750 SR and enables service interworking between different link layer technologies. A typical use of this application is in a Layer 2 VPN when upgrading a hub site to Ethernet while keeping the spoke sites with their existing Frame Relay or ATM IPv4 routed encapsulation.
Note: Ipipe VLL is not supported in System Profile B. To determine if Ipipes are currently
provisioned, use the show service service-using ipipe command before
configuring profile B.
Figure: IP interworking VLL (Ipipe)
Note: The Ipipe is a point-to-point Layer 2 service. All packets received on one SAP of the Ipipe
are forwarded to the other SAP. No IP routing of customer packets occurs.