Cabletron Systems 04-0053-01 , 2.2.7 Using LNNI

2-16 SmartSwitch ATM User Guide

Creating an Emulated LAN IP Over ATM and LANE

Currently, the SmartSwitch 6500 is the only SmartSwitch ATM switch that supports logical multicasting. For this

reason, if you are connecting to LANE services across an ATM WAN using multiple PVPs and if client join requests

for the same ELAN are received over different PVPs, you must use a SmartSwitch 6500 as the LANE services switch.

If on the other hand, your WAN connection consists of a single PVP, any of the SmartSwitch ATM switches can be

used as the LANE services switch.

The rules for selecting the appropriate SmartSwitch ATM switch for providing LANE services across an ATM WAN

are summarized below:

•A single PVP connection terminated on the LANE server switch with a single virtual port — Any

SmartSwitch ATM switch as the LANE server (physical BUS multicasting)

•Multiple PVP connections terminated on the LANE server switch through virtual ports on the same

physical port, where each PVP supports client connection requests for separate ELANs — Any

SmartSwitch ATM switch (physical BUS multicasting)

•Multiple PVP connections terminated on the LANE server switch through virtual ports on d if ferent

physical ports — Any SmartSwitch ATM switch (physical BUS multicasting)

•Multiple PVP connections terminated on the LANE server switch through virtual ports on the same

physical port, where each PVP supports client connection requests for the same ELAN —

SmartSwitch 6500 only (logical BUS multicasting required).

2.2.7 Using LNNI

SmartSwitch ATM switches provide support for LNNI. LNNI gives LANE redundancy and load-sharing capabilities

by allowing multiple LECSs to exist on the same network, and by allowing multiple LES/ BUSs and SMSs to service

the same ELANs.

Note For an explanation of all LNNI related commands and parameters, see the

SmartSwitch ATM Switch Reference Manual.

As many as eight (8) LECSs (one per SmartSwitch ATM switch) can be deployed on the same network; each LECS

can support multiple ELANs. This is especially useful on large, mission-critical networks and eliminates the possibility

of the LECS being a potential single point-of-failure. If, for some reason, LANE services go down on a particular

switch, the clients that this switch supports can reestablish their connection to their ELAN through one of the other

LECSs (see Figure2-3).