Cisco 7970G Administration Guide - Page 58

Providing Power to the Phone Chapter 2 Preparing to Install the Cisco Unified IP Phone on Your Network Phone Power Consumption and Display Brightness The power consumed by a phone depends on its power configuration. See Table 2-1 for a power configuration overview. See Table 2-2 for the maximum power consumed by a phone for each configuration option and the correlating phone screen brightness level. Note Power consumption values shown in the table include power losses in the cable that connects the phone to the switch. Table 2-2 Power Consumption and Display Brightness for Power Configurations Phone Model Cisco Unified IP Phone 7970G Cisco Unified IP Phone 7971G-GE Power Configuration Max. Power Phone Consumed Screen from a Switch Brightness Cisco prestandard PoE from a switch that supports a maximum of 7 W power per port, with bidirectional power negotiation enabled 6.3 W Approx. 1/2 Cisco prestandard PoE from a Cisco Switch that supports 7 W or 15.4 W power per port, without bidirectional power negotiation 6.3 W Approx. 1/2 IEEE 802.3af Class 3 power from a Cisco switch, without bidirectional power negotiation 6.3 W Approx. 1/2 IEEE 802.3af Class 3 power from a third-party switch 6.3 W IEEE 802.3af Class 3 power from a Cisco switch, with 10.25 W bidirectional power negotiation enabled Approx. 1/2 Full1 Cisco prestandard PoE from a Cisco Switch that 10.25 W Full supports 15.4 W power per port, with bidirectional power negotiation enabled External power - Full IEEE 802.3af Class 3 power from a Cisco switch (with 15.4 W or without bidirectional power negotiation enabled) or from a third-party switch Near full External power - Full Cisco Unified IP Phone 7970G/7971G-GE Administration Guide for Cisco Unified Communications Manager 6.1 2-6 OL-14626-01