Примечания к выпуску для Cisco Cisco 4402 Wireless LAN Controller
R E V I E W D R A F T — C I S C O C O N F I D E N T I A L
11
Release Notes for Cisco Wireless LAN Controllers and Lightweight Access Points for Release 3.2.210.0
OL-xxxxx-xx
Important Notes
Voice WLAN Configuration
Cisco recommends that load balancing always be turned off in any wireless LAN that is supporting
voice, regardless of vendor. When load balancing is turned on, voice clients can hear an audible artifact
when roaming, and the handset is refused at its first reassociation attempt.
voice, regardless of vendor. When load balancing is turned on, voice clients can hear an audible artifact
when roaming, and the handset is refused at its first reassociation attempt.
Inter-Subnet Roaming
Currently, multicast traffic cannot be passed during inter-subnet roaming.
Operating Mesh Networks Through Switches and Routers
In mesh networks that operate through low-speed switches and routers, access points can disconnect
from the controller, causing the controller to generate alerts.
from the controller, causing the controller to generate alerts.
Heavily Loaded Controller CPU
When the controller CPU is heavily loaded (for example, when doing file copies or other tasks), it does
not have time to process all of the ACKs that the NPU sends in response to configuration messages.
When this happens, the CPU generates error messages. However, the error messages do not impact
service or functionality.
not have time to process all of the ACKs that the NPU sends in response to configuration messages.
When this happens, the CPU generates error messages. However, the error messages do not impact
service or functionality.
RADIUS Servers and the Management VLAN
The RADIUS server can be on any subnet as long as it can be reached by the management VLAN subnet.
The controllers can be managed via the management VLAN subnet from any other subnet that can reach
the management VLAN subnet.
the management VLAN subnet.
Cisco 7920 Wireless IP Phone Support
When using Cisco 7920 Wireless IP Phones with controllers, make sure that the phones and controllers
are configured as follows:
are configured as follows:
•
Aggressive load balancing must be disabled on a per-controller basis. Otherwise, the initial roam
attempt by the phone may fail, causing a disruption in the audio path.
attempt by the phone may fail, causing a disruption in the audio path.
•
The QoS Basis Service Set (QBSS) information element (IE) must be enabled. The QBSS IE enables
the access points to communicate their channel usage to wireless devices. Because access points
with high channel usage might not be able to handle real-time traffic effectively, the 7920 phone uses
the QBSS value to determine if it should associate with another access point. Use the following
commands to enable the QBSS IE:
the access points to communicate their channel usage to wireless devices. Because access points
with high channel usage might not be able to handle real-time traffic effectively, the 7920 phone uses
the QBSS value to determine if it should associate with another access point. Use the following
commands to enable the QBSS IE:
–
sh wlan summary
Note
Use this command to determine the WLAN ID number of the WLAN to which you want
to add QBSS support.
to add QBSS support.