Avaya 580, 882 Auto-Increment , Trigger (Multiplier) , Threshold (Util%)

9-8 User Guide for the Avaya P580 and P882 Multiservice Switches, v6.1
Chapter 9
Figure 9-2. Address Forwarding Table Configuration
Auto-Increment Auto-Increment is the Enable/Disable setting for the Auto-Sizing feature. If
Auto-Increment is enabled, the swi tch will automatically increase the hash
table size provided two conditions are met.See Figure9-1 for enabling or
disabling Auto-Increment HT size.
Trigger (Multiplier) The first condition is the Trigger (Multiplier), which sets a minimum
threshold for the number of learned entries a VLAN must have before the
switch will consider increasing the Hash Table size. This prevents the
Avaya Multiservice Switch from resizing Hash Tables for VLANs who
have only a few AFT entries. This threshold is 12 times the Hash Table size.
For Example: If a VLAN is created w ith an Initial Hash Table Size of 64,
the trigger would be 12 times 64 = 768 learned entries. If there are more
than 768 learned entries, the second condition is evaluated.
Threshold (Util%) The second condition is met if Bucket Utilization drops below the
Threshold (Util%), which by default is 40%. The switch will compensate
for the poor utilization by doubling the Hash Table. 40% is recommended
for most applications.
Resizing results in the switch utilizing AFT memory more e ffi ciently. When
the switch resizes the Hash Table, all entries are flushed and must be
relearned.