178 Appendix B Troubleshooting WLAN IP Telephony installationsNortel switchesThis section contains configuration information for Nortel switches.Nortel WLAN Security SwitchThe 2350, 2360, and 2380 model switches have the following requirements:• load 4.1.14• configure radio-profile voice dtim-interval 3• configure radio-profile voice active-scan disable (prevents the AP fromgoing off-channel to scan)• radio-profile voice WMM enabledCisco access points and switchesThis section contains configuration information for selected Cisco accesspoints and switches.Cisco Aironet 1200 SeriesEnsure that the software is 12.3.7(JA3). This requirement is current as ofNovember 2006 and is subject to change.Configure the following settings:• dtim-interval 3• protocol 119 enabled• less than 10 ms voice latency• voice WMM enabledFor more information, see the Cisco Aironet 1200 Series User Guide.Nortel WLAN Security Switch 2270 and the Cisco 4400 SeriesWLAN ControllerAlpha The 2270 and 4400 infrastructure has the following requirements:• Turn off aggressive load balancing.• Disable MAC filtering authentication for voice SSID and use only staticWEP (40 or 104 bit) encryption.• Configure 802.11b radio data rates as follows:— 1Mb/s—Mandatory— 2Mb/s—Mandatory— 5.5Mb/s—Supported— 11Mb/s—Supported• Uncheck enable short preamble.Nortel Communication Server 1000WLAN IP Telephony Installation and CommissioningNN43001-504 01.02 StandardRelease 5.0 15 June 2007Copyright © 2004-2007, Nortel Networks.
