Cisco Systems OL-6415-04 manual Configuring Fragmentation Threshold, Fragment-threshold value

Chapter 2 Configuring Radio Settings

Configuring Fragmentation Threshold

	Command	Purpose
Step 4
	end	Return to privileged EXEC mode.
Step 5
	copy running-config startup-config	(Optional) Save your entries in the configuration file.

Use the no form of the command to reset the setting to defaults.

Configuring Fragmentation Threshold

The fragmentation threshold determines the size at which packets are fragmented (sent as several pieces instead of as one block). Use a low setting in areas where communication is poor or where there is a great deal of radio interference.

The default setting is 2338 bytes. Beginning in privileged EXEC mode, follow these steps to configure the fragmentation threshold:

	Command	Purpose
Step 1
	configure terminal	Enter global configuration mode.
Step 2
	interface dot11radio { 0 1 }	Enter interface configuration mode for the radio interface. The
		2.4-GHz radio is radio 0, and the 5-GHz radio is radio 1.
Step 3
	fragment-threshold value	Set the fragmentation threshold. Enter a setting from 256 to
		2346 bytes for the 2.4-GHz radio. Enter a setting from 256 to
		2346 bytes for the 5-GHz radio.
Step 4
	end	Return to privileged EXEC mode.
Step 5
	copy running-config startup-config	(Optional) Save your entries in the configuration file.

Use the no form of the command to reset the setting to defaults.

Enabling Short Slot Time for 802.11g Radios

You can increase throughput on the 802.11g, 2.4-GHz radio by enabling short slot time. Reducing the slot time from the standard 20 microseconds to the 9-microsecond short slot time decreases the overall backoff, which increases throughput. Backoff, which is a multiple of the slot time, is the random length of time that a station waits before sending a packet on the LAN.

Many 802.11g radios support short slot time, but some do not. When you enable short slot time, the wireless device uses the short slot time only when all clients associated to the 802.11g, 2.4-GHz radio support short slot time.

Short slot time is supported only on the 802.11g, 2.4-GHz radio. Short slot time is disabled by default.

		Command	Purpose
	Step 1
		router(config-if)# slot-time-short	In radio interface mode, enter this command to enable short slot
			time.
	Step 2
		no slot-time-short	(optional) Enter no slot-time-shortto disable short slot time.
	Cisco Wireless ISR and HWIC Access Point Configuration Guide
2-28			OL-6415-04