Cabletron Systems 04-0053-01 Manual De Usuario

4-4   SmartSwitch ATM User Guide

IISP Routes

  Routing

Figure 4-2 Routes needed for a second IISP switch

4.2.2

IISP Link Timing

By default, if an IISP link loses connectivity, the link fails after three (3) seconds. This short amount of time is designed 
as a buffer in case of minor latency. By waiting three seconds before releasing resources and tearing down the 
connection, a minor latency occurrence (less than three seconds) will not bring down the route.

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

 command to control the time required for the 

SmartSwitch ATM switch to assume an IISP route has failed. 

For example, two SmartSwitch ATM switches are connected with parallel IISP 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 IISP links, that link’s port immediately frees up all resources, and all traffic 
between the switches is routed through the remaining IISP link. 

Notice that the 

 command controls the 

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

basis).

Remember that while some special network configurations may require the 

 to be zero (0), setting 

 to less than three seconds 

may cause an IISP route to fail unnecessarily. For this reason, care should be 
taken when setting the 

 to less than three seconds.