| Author: | Herbert Haas |
|---|---|
| Address: | herbert AT perihel DOT at http://www.perihel.at/dcom |
| Revision: | 0.5 |
| Date: | 2007-10-29 |
| Copyright: | Copyright (c) 2007 Herbert Haas. |
Abstract
This document summarizes important facts about Cisco's Wireless Control System (WCS). It is not a WLAN tutorial. Note that Cisco-related explanations or recommendations are provided as is, without any warranty - please consult www.cisco.com for more detailed information. The reader should already be familiar with WLAN fundamentals (see e. g. my WLAN lecture notes). If you find any mistakes please send me an E-Mail, thanks!
WCS version 4 runs on Windows 2003 and Red Hat Enterprise Linux ES 4.0 and AS 4.0 servers.
WLC version should not be greater than WCS version.
Login: root/public new: root/Public1! (since version 4.1)
All monitor data available for 7 days (e.g. for trending analysis)
Don't block port 169 otherwise WCS can't receive any traps
Calibration 150 data points are required, 50 locations
When clearing alarm, underlying event is not cleared
HTTP and HTTPS ports can be changed during installation
Search criteria to search WLCs: name, networks, IP address
Audit trail should be purged manually
Installation log will be put on the desktop of the server
A WCS converted from a WLSE can handle up to 100 Controllers and 1500 APs.
Backup Automatically - Can enforces WLCs to perform periodic (1:00 am daily) configuration backups via TFTP on specified TFTP server. Period can be changed.
Note: The TFTP server cannot run on the same computer as the WCS, because the WCS and the TFTP server use the same communication port.
Config Groups - Group WLCs that should have same mobility group name and similar configuration. Assign templates to that group and push them to all WLCs in the group.
Polling value should equal to or greater than RFID tag beacon interval. Cisco recommends that the RFID timeout value on your WLC should be 8-10 times the tag beacon rate. If the RFID beacon is 10s, the timeout should be between 80-100 seconds:
(WLC) >config rfid timeout 80
LAPs must be in normal, monitor or H-REAP mode.
Clients and LAPs must support CCXv2 or higher (1030 does not!). On configured intervals the LAPs send broadcast radio measurement requests for every SSID. CCXv2-clients reply with probe requests on all channels specified in the measurement request. On version 4.0 this was a broadcast message and the LAP calculated RF parameters which were send to the Location Appliance. Since version 4.1 the clients send unicast probe requests and send RF parameters from their perspective.
WLC software release 4.1 also improves the ability of the Location Appliance to accurately interpret the location of a device through a new CCXv4 feature called location-based services. The controller issues a path-loss request to a particular CCXv4 client. If the client chooses to respond, it sends a path-loss measurement report to the controller. These reports contain the channel and transmit power of the client.
On WLC enable CCX Location Measurement under Wireless > 802.11 a|b/g > Network. Optionally change the interval (default: 60 sec).
LAPs must be separated every 17-20 meters (50-70 feet).
Devices must be detected at signals greater than -75 dBm for the WLCs to forward information to the Location Appliance.
Active RFID tags do not associate to LAPs and therefore are not affected by any WLAN or WLC settings. RFID tags send L2 multicast packets which are automatically forwarded by the LAP if the WLC is configured for RFID Tag Data Collection:
(Cisco Controller) >config rfid status enable
The WCS and Location Server poll the SNMP table of the WLC in order to view tag information.