Safety and Performance Information
Power Outage
Your access to emergency service through the phone requires that the phone receive power. If a power interruption occurs, service or emergency calling service dialing does not function until power is restored. If a power failure or disruption occurs, you may need to reset or reconfigure the equipment before you can use service or emergency calling service dialing.
External Devices
We recommend that you use good-quality external devices that are shielded against unwanted radio frequency (RF) and audio frequency (AF) signals. External devices include headsets, cables, and connectors.
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]. |
Phone Behavior During Times of Network Congestion
Anything that degrades network performance can affect phone audio and, in some cases, can cause a call to drop. Sources of network degradation can include, but are not limited to, the following activities:
-
Administrative tasks, such as an internal port scan or security scan.
-
Attacks that occur on your network, such as a Denial of Service attack.
Feedback