7961G and Power Consumption

Question

I have a 3750 with 48 ports.
I can only use 24 ports with 7961's. After that, no more power can be drawn from the switch.
I noticed that the 7961's are using 15.4watts of power.
7960's used 7.7watts mode.
Can the 7961's use 7.7watts mode?
This is not configurable on the switch.
Is it configurable on the IP Phone??
I can't find any documentation on Cisco's web site in regards to 7961 power consumption (only 7960 power consumption).
thanks,
Paul

Answer 1

Hi Paul,
Are these phones 7961G or 7961G-GE? The 7961G are a class 2 device (7.7 watts) and the 7961G-GE phones are a class 3 device (15.4 watts).These are not configurable settings.
Each Cisco Catalyst 3750-24PS or Cisco Catalyst 3750-48PS switch can optionally detect the PD Power Classification signature and budget the appropriate power. This reduces the maximum power that must be budgeted by the switch and provisioned in the wiring closet. The Cisco Catalyst 3750 PoE switches have **370W**(this is enough for 48 class 2 devices @ 7.7 watts 48x7.7 = 369.6 watts) available for Power over Ethernet, which is shared by all 24/48 ports. The switch allocates the maximum power a PD needs.
Have a look at these Cisco docs;
Cisco Unified IP Phone 7961G
Power Requirements The phone is interoperable with Cisco Pre-standard PoE and with IEEE 802.3af PoE (the phone is a Class 2 device); 48 VDC is required; it can be supplied locally at the desktop using an optional AC-to-DC power supply (part number CP-PWR-CUBE-3=).
From this doc;
http://www.cisco.com/en/US/products/hw/phones/ps379/products_data_sheet0900aecd802ff020.html
Cisco Unified IP Phone 7961G-GE
Power Requirements The phone supports the IEEE 802.3af PoE (the phone is a Class 3 device) standard; 48 VDC is required; it can be supplied locally at the desktop using an AC-to-DC power supply (part number CP-PWR-CUBE-3=).
The Cisco Unified IP Phone 7961G-GE supports IEEE 803.af Power over Ethernet (PoE). It also can be powered locally with a power supply (part number CP-PWR-CUBE-3). **Note: The Cisco Unified IP Phone 7961G-GE does not support Cisco Pre-standard PoE.**
From this doc;
http://www.cisco.com/en/US/products/hw/phones/ps379/products_data_sheet0900aecd802ff030.html
Hope this helps!
Rob
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