Alcatel Carrier Internetworking Solutions Switch/Router ユーザーズマニュアル

Page 17-35

Two additional enhancements are also included with the Fast Spanning Tree feature for 
improved performance: Truncating Tree Timing and Speedy Tree Protocol. 

Truncating Tree Timing allows Designated Ports attached to Point-to-Point links to change to 
Forwarding mode faster, by utilizing two extra bits in the Configuration 

BPDU

 for 

communication between neighboring bridges. This enhancement promotes quicker 
restoration of service between communicating stations and reduced flooding of traffic during 
relearning of station location information.

Speedy Tree Protocol significantly improves reconfiguration performance by allowing inferior 
information sent by the designated bridge for each 

LAN

 to be accepted, rather than timed out. 

Additionally, information previously received expires immediately on link failure. In both 
cases, spanning tree recomputation occurs, which can cause changes in both root and 
designated ports.

Both Truncating Tree Timing and Speedy Tree Protocol are enabled by default. These features 
are configured by editing the following lines in the command file (

):

To disable the Truncating Tree Timing feature, change the numeric entry for 

 from 

 to 

. (To re-enable the feature, change the numeric entry back to 

.)

To disable the Speedy Tree Protocol feature, change the numeric entry for 

 from 

 to 

. (To re-enable the feature, change the numeric entry back to 

.)

♦ Important Note ♦

Do not attempt to edit the command file (

)

unless you have had significant experience working 
with files of this type. For additional information, see 
Editing Text Files in Chapter 7, “Managing Files.”