LAN Emulation Operation 2-11
BUS Connection During the BUS Connection stage, the LEC:
1Sends an LE-ARP (LAN Emulation-Address Resolution Protocol) request to the LES containing the target MAC address FF-FF-FF-FF-FF-FF (broadcast MAC address).
The LES returns an LE-ARP response containing the ATM address of the emulated LAN’s BUS.
2Establishes connections to the BUS for transmitting and receiving multicast and unknown unicast traffic.
Data Movement In the Data Movement stage, the LEC:
■Sends and receives multicast MAC frames over the connections to the BUS.
■Sends and receives unknown unicast MAC frames (unicast MAC frames for which the corresponding ATM address on the emulated LAN is unknown) over the connections to the BUS. At the same time, the LEC conducts an LE-ARP exchange to associate the MAC address with the ATM address of another station on the emulated LAN.
■After a MAC/ATM address binding is resolved using LE-ARP, establishes a Data Direct VCC to that ATM address. After the Data Direct VCC is set up between two LECs, a Flush request is sent via the bus to signal to the receiving LEC to stop sending Data via the bus and to start sending data over the established Data Direct VCC. The receiving LEC responds with a Flush response via the bus to clear the bus channel. Any unicast frames received from the ATM address from the time the LEC sends out the Flush request until the time it receives the Flush response are buffered. The buffered frames are sent out over Data Direct VCC after the LEC receives the Flush command instead of over the bus.
■Disconnects a Data Direct VCC that remains idle for a specified timeout period.
