Usb Port Information - Cisco 8800 Series Administration Manual

• Move the external device away from the source of the RF or AF signals.
• Route the external device cables away from the source of the RF or AF signals.
• Use shielded cables for the external device, or use cables with a better shield and connector.
• Shorten the length of the external device cable.
• Apply ferrites or other such devices on the cables for the external device.
Cisco cannot guarantee the performance of external devices, cables, and connectors.
In European Union countries, use only external speakers, microphones, and headsets that are fully compliant
Caution
with the EMC Directive [89/336/EC].

USB Port Information

The Cisco IP Phones 8851, 8851NR, 8861, 8865, and 8865NR support a maximum of five devices that connect
to each USB port. Each device that connects to the phone is included in the maximum device count. For
example, your phone can support five USB devices on the side port and five additional standard USB devices
on the back port. Many third-party USB products count as multiple USB devices; for example, a device
containing a USB hub and headset can count as two USB devices. For more information, see the USB device
documentation.
• Unpowered hubs are not supported, and powered hubs with more than four ports are not supported.
Note
• USB headsets that connect to the phone through a USB hub are not supported.
Each Cisco IP Phone 8800 Key Expansion Module (KEM) connected to the phone counts as a USB device.
If three KEMs are connected to the phone, these count as three USB devices.
Phone Configuration Files
Configuration files for a phone are stored on the TFTP server and define parameters for connecting to Cisco
Unified Communications Manager. In general, any time you make a change in Cisco Unified Communications
Manager that requires the phone to be reset, a change is automatically made to the phone configuration file.
Configuration files also contain information about which image load the phone should be running. If this
image load differs from the one currently loaded on a phone, the phone contacts the TFTP server to request
the required load files.
If you configure security-related settings in Cisco Unified Communications Manager Administration, the
phone configuration file will contain sensitive information. To ensure the privacy of a configuration file, you
must configure it for encryption. For more information, see the documentation for your particular Cisco
Unified Communications Manager release. A phone requests a configuration file whenever it resets and
registers with Cisco Unified Communications Manager.
A phone accesses a default configuration file named XmlDefault.cnf.xml from the TFTP server when the
following conditions exist:
Cisco IP Phone 8800 Series Administration Guide for Cisco Unified Communications Manager
USB Port Information
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