Cabletron Systems 04-0053-01 User Manual

3-12   SmartSwitch ATM User Guide

Managing Parallel PNNI Links

  PNNI Routing

However, certain time-sensitive implementations of PNNI may require that link fail occur either immediately or after 
a period of time longer than three seconds. Use the 

 command to control the time required 

for the SmartSwitch ATM switch to assume a link has failed. 

For example, two SmartSwitch ATM switches are connected with parallel PNNI links. To configure the switches to 
immediately recognize any lapse in traffic as a downed link, enter the following on both switches:

SmartSwitch # set linkmonitortimeout

TimeoutValue(3)                           : 0  

SmartSwitch #

If a traffic lapse occurs on one of the links, that link’s port immediately frees up all resource, and all traffic is routed 
between the switches through the remaining link. 

Notice that the 

 command controls the 

 on a switch-wide basis (not a per-port 

basis).

Remember that while some special uses of PNNI may require the 

 

to be zero (0), setting the 

 to less than three seconds may cause 

the PNNI network to “bounce,” entering a state of constant (and unnecessary) 
reconfiguration. For this reason, care should be taken when setting the 

 to less than three seconds.