Usb Port Information; Sip And Nat Configuration; Sip And The Cisco Ip Phone - Cisco 8800 Series Manual

USB Port Information

Depending on the quality of these devices and their proximity to other devices, such as mobile phones or
two-way radios, some audio noise may still occur. In these cases, we recommend that you take one or more
of these actions:
• 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.
Caution In European Union countries, use only external speakers, microphones, and headsets that are fully compliant
with the EMC Directive [89/336/EC].
USB Port Information
The Cisco IP Phones 8851, 8861, and 8865 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 more 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.
Note • Unpowered hubs are not supported, and powered hubs with more than four ports are not supported.
• USB headsets that connect to the phone through a USB hub are not supported.
Each key expansion module connects to the phone counts as a USB device. If three key expansion modules
are connected to the phone, these count as three USB devices.

SIP and NAT Configuration

SIP and the Cisco IP Phone

The Cisco IP Phone uses Session Initiation Protocol (SIP), which allows interoperation with all IT service
providers that support SIP. SIP is an IETF-defined signaling protocol that controls voice communication
sessions in an IP network.
SIP handles signaling and session management within a packet telephony network. Signaling allows call
information to be carried across network boundaries. Session management controls the attributes of an
end-to-end call.
Cisco IP Phone 8800 Series Multiplatform Phone Administration Guide for Release 11.3(1) and Later
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Technical Details