Avaya P550R User Manual page 19

Avaya P550R/P580/P880/P882 Multiservice Switch ATM Uplink Module User Guide, Version 2.0
LEC (LAN Emulation Client) - An entity in an end system
that performs data forwarding, address resolution, and other
control functions. A LEC also provides a standard LAN
service interface to any higher-layer entity that interfaces to
the LEC. Each LEC is identified by a unique ATM address,
and is associated with one or more Media Access Control
(MAC) addresses reachable through that ATM address
LECS (LAN Emulation Configuration Server) - An entity
that assigns individual LANE clients to particular Emulated
LANs (ELANs) by directing them to the LAN Emulation
Server (LES) that corresponds to the ELAN. There is logically
one LECS per administrative domain, and this serves all
ELANs within that domain.
LES (LAN Emulation Server) - An entity that implements
the control function for a particular ELAN. There is only one
logical LES per ELAN, and it is identified by a unique ATM
address.
BUS (Broadcast and Unknown Server) - A Multicast server
used in ELANs to flood traffic addressed to an unknown
destination and to forward multicast and broadcast traffic to
the appropriate clients.
The basic concepts are consistent between LANE V1 and LANE V2,
however, there are some differences between them. The main
difference is that LANE V2 provides QoS support and multiplexing
of Virtual Circuits (VCs).
LANE is one of the mechanisms the ATM Uplink module uses to
simulate a LAN over the ATM network. By implementing a LANE
client in the ATM Uplink module, the ATM network can seamlessly
provide connectionless LAN and multicast capabilities to the rest of
the Ethernet LAN.
The logical topology of the ATM Uplink module interfaces is
different from the physical connections. LECs are configured on the
ATM Uplink module. A LEC is not associated with a physical port,
but instead is associated with a LANE server that forms an ELAN.
A LEC is treated similarly to an Ethernet port of the Avaya system
and is associated with a Virtual LAN (VLAN). A LEC is represented
and configured as a switch port in the Avaya switch. Each VLAN
may have only one LEC per ATM Uplink module, and each module
may have only one LEC per ELAN.
Overview
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