This document lists suggestions that are helpful when Symbol handheld
devices are deployed in a controller based environment.
Cisco recommends that you have knowledge of these topics:
The information in this document is based on the Wireless LAN
Controller (WLC) 4400 that runs version 220.127.116.11.
The information in this document was created from the devices in a
specific lab environment. All of the devices used in this document started with
a cleared (default) configuration. If your network is live, make sure that you
understand the potential impact of any command.
Technical Tips Conventions for more information on document
This is the list of suggestions that was found to improve
interoperability of handheld devices in a controller based environment:
If you are in an environment where older switches are used, the
access points (APs) will join the WLC but will not have enough power.
Therefore, the radios will not come up. A power injector needs to be used to
provide sufficient power.
config ap power injector enable <AP Name>
Make sure you are running WLC version 18.104.22.168 or
Symbol devices running earlier firmware version might not roam
properly. It sticks to the AP originally associated. This is a known issue and
Symbol has released a Beta Version to fix this. Download the Beta Version from
Aironet IE—Aironet IE is a Cisco proprietary
attribute used by Cisco devices for better connectivity. Disable Aironet IE.
From the WLC GUI go to the WLANs tab. Click on the WLAN to
which the symbol devices connects. Go to the Advanced tab and
uncheck Aironet IE.
Check if the device is CCX certified to ensure interoperability with
Cisco WLCs. Certain symbol devices, such as MC75 and MC5590 (under MPA 1.5
platform), are CCXv4 certified.
Devices such as MC9090 WM 6.1, MC9090 - VGA WM 6.1, MC9094 WM 6.1,
MC7090 WM 6.1, MC7095 WM 6.1, MC7090 WM 6.1, MC7095 WM 6.1, MC70x4 WM 6.1,
MC7598 WM 6.1, MC3090 CE5 Pro, MC3090 CE5 Core, WT4090 CE 5.0(MPA 1.0), and
VC5090 CE5.0(MPA 1.0) are CCXv3 certified.
Modify the DTIM interval. Good performance has been
seen with the DTIM setting of 6.
Client Exclusion per WLAN—This option is normally
used to exclude certain clients from accessing the WLAN. Disable client
exclusion to make sure that Symbol device is not in the excluded list.
MFP—Management Frame Protection is a Cisco
properietary feature introduced to ensure the integrity of the management
frames, such as de-authentication, disassociation, beacons, and probes wherein
the AP protects the management frames that it transmits when it adds a Message
Integrity Check Information Element (MIC IE) to each frame. Any attempt made by
the intruders to copy, alter, or replay the frame invalidates the MIC, which
causes any receiving AP that is configured to detect MFP frames, to report the
discrepancy. Disable MFP on the
Load balancing—This feature is used to prevent too
many clients from associating to the WLC. Disable this feature to ensure that
the device is not rejected by any chance. Click on the
Controller tab. Navigate to the General menu
to disable Aggressive Load Balancing.
Radio Preambles—The radio preamble (sometimes called
a header) is a section of data at the head of a packet that contains
information that the wireless device and client devices need to send and
receive packets. Long Preamble increases interoperability
between the WLC and the client. Click on the Wireless
Navigate to 802.11 b/g/n and click the
Network option, then uncheck Short
Disable the Client Exclusion Policies Globally. Click on the
Security tab and navigate to Client Exclusion
Policies under the Wireless Protection Policies menu.
Uncheck the options under Client Exclusion Policies.