Abstract: Transparent redundancy may be achieved at a MPLS-MPLS hierarchical boundary or a BMA-MPLS hierarchical boundary by utilizing local repair mechanisms extant in each domain to select automatically the same boundary network devices as the primary and secondary boundary network devices. In the MPLS domain, two LERs advertise the ability to forward traffic to a phantom LER and map all traffic originated into that domain as having been on a path originating at the phantom LER. This will cause the LERs to appear as being one hop away from the phantom LER, causing MPLS to assume the real LERs are part of a LSP terminating at the phantom LER. MPLS local repair will thus establish one of the LERs as the primary LER and the other LER as the secondary LER. In an Ethernet domain, each boundary network device is treated analogously to a router in the VRRP scheme for routers.

Abstract: By using a LAN emulation in an ATM environment, end systems such as workstations etc. can connect to the ATM network while software applications interact as if they are attached to a traditional LAN. The invention is a simple technique for emulating a LAN on an ATM network. According to the invention, each end system is identified by hub and port identifiers which represent a hub and a port of the hub to which the end system is connected. By labelling each ATM cell, and proper label translation at hubs, a LAN can be emulated without using network servers which would introduce cumbersome extra procedures.