Approaches of Using ATM in Backbone
LAN Emulation (LANE)
- Breaking LAN frame into 48-byte long blocks and transmit them in an ATM cell
- Called encapsulation and done by edge switches
- Reassembling done at the destination edge switch and LAN frame is sent to the LAN
- Requires translating of MAC addresses to VC Identifiers (assuming VCs are setup already)
- Performance suffers due to encapsulation and connection management
Multiprotocol over ATM (MPOA)- LANE extension
- Uses IP addresses in addition to MAC addresses
- If same subnet, use MAC address; otherwise use IP
- ATM backbone operating like a network of brouters