Configuring the System for SpectraLink NetLink Telephones

Information About SpectraLink NetLink Telephones

For the best integration with the Cisco UWN solution, SpectraLink NetLink Telephones require an extra operating system configuration step: enable long preambles . The radio preamble (sometimes called a header) is a section of data at the head of a packet that contains information that wireless devices need when sending and receiving packets. Short preambles improve throughput performance, so they are enabled by default. However, some wireless devices, such as SpectraLink NetLink phones, require long preambles.

Configuring SpectraLink NetLink Phones

Enabling Long Preambles (GUI)

Procedure

Step 1

Choose Wireless > 802.11b/g/n > Network to open the 802.11b/g Global Parameters page.

Step 2

If the Short Preamble check box is selected, continue with this procedure. However, if the Short Preamble check box is unselected (which means that long preambles are enabled), the controller is already optimized for SpectraLink NetLink phones and you do not need to continue this procedure.

Step 3

Unselect the Short Preamble check box to enable long preambles.

Step 4

Click Apply to update the controller configuration.

Note 

If you do not already have an active CLI session to the controller, we recommend that you start a CLI session to reboot the controller and watch the reboot process. A CLI session is also useful because the GUI loses its connection when the controller reboots.

Step 5

Choose Commands > Reboot > Reboot > Save and Reboot to reboot the controller. Click OK in response to this prompt: 


Configuration will be saved and the controller will be rebooted. Click ok to confirm.

The controller reboots.
Step 6

Log back onto the controller GUI to verify that the controller is properly configured.
Step 7

Choose Wireless > 802.11b/g/n > Network to open the 802.11b/g Global Parameters page. If the Short Preamble check box is unselected, the controller is optimized for SpectraLink NetLink phones.

Enabling Long Preambles (CLI)

Procedure

Step 1

Log on to the controller CLI.
Step 2

Enter the show 802.11b command and select the Short preamble mandatory parameter. If the parameter indicates that short preambles are enabled, continue with this procedure. This example shows that short preambles are enabled: 


Short Preamble mandatory....................... Enabled

However, if the parameter shows that short preambles are disabled (which means that long preambles are enabled), the controller is already optimized for SpectraLink NetLink phones and you do not need to continue this procedure.

Step 3

Disable the 802.11b/g network by entering this command:

config 802.11b disable network

You cannot enable long preambles on the 802.11a network.
Step 4

Enable long preambles by entering this command:

config 802.11b preamble long

Step 5

Reenable the 802.11b/g network by entering this command:

config 802.11b enable network

Step 6

Enter the reset system command to reboot the controller. Enter y when the prompt to save the system changes is displayed. The controller reboots.

Step 7

Verify that the controller is properly configured by logging back into the CLI and entering the show 802.11b command to view these parameters: 


802.11b Network................................ Enabled
Short Preamble mandatory....................... Disabled

These parameters show that the 802.11b/g network is enabled and that short preambles are disabled.

Configuring Enhanced Distributed Channel Access (CLI)

To configure 802.11 enhanced distributed channel access (EDCA) parameters to support SpectraLink phones, use the following CLI commands:

config advanced edca-parameter {custom-voice | optimized-video-voice | optimized-voice | svp-voice | wmm-default}

where

  • custom-voice enables custom voice EDCA parameters

  • optimized-video-voice enables combined video-voice-optimized parameters

  • optimized-voice enables non-SpectraLink voice-optimized parameters

  • svp-voice enables SpectraLink voice priority (SVP) parameters

  • wmm-default enables wireless multimedia (WMM) default parameters


Note

To propagate this command to all access points connected to the controller, make sure to disable and then reenable the 802.11b/g network after entering this command.