Hi Youness,

You should be good to go with the IP Phone 7960 and the Catalyst 3560. Have a look;

The 7940G/7941G and 7960G/7961G are class 2 devices (7.7 watts) and the 7941G-GE/7961G-GE phones are class 3 devices (15.4 watts).These are not configurable settings.

The 3560G-48PS supports 48 PoE Class 2 (7.7W) and 24 PoE Class 3 (15.4W) devices, with a total switch Maximum Power Consumption of 590 W.

"When Cisco Unified IP phones are connected to common switches such as the Cisco Catalyst 3560 Series Switches or Cisco Catalyst 3570 Switches, the switch can automatically detect the phone type and provide the exact amount of power that the phone needs. The use of Cisco Discovery Protocol provides this greater granularity to the power classification, allowing more accurate reporting of power consumption, and a higher density of phones on the same switch.

Q. What IP phone models support the Cisco pre-standard method of powered device detection?

A. These Cisco IP phones can accept Cisco pre-standard PoE from a card integrated with a Cisco Catalyst switch or a Catalyst in-line power patch panel:

7985G

7960G

7940G

7910G

7910G + SW

7912G

7905G

7902G

These phones can draw local power from a power cube (CP-PWR-CUBE-2=) in addition to a country or regionally specific power cord (CP-PWR-CORD-xx=).

Q. What IP phone models support the IEEE standard method of powered device detection?

A. These Cisco IP phones support IEEE 802.3af PoE:

7961G

7961G-GE

7971G-GE

7941G

7931G

7911G

7941G-GE

Note: These Cisco IP phones support both the Cisco pre-standard PoE and IEEE 802.3af PoE:

7970G

7906G

From this new doc;

Power over Ethernet (PoE) Power Requirements FAQ

http://www.cisco.com/en/US/products/hw/phones/ps379/products_qanda_item09186a00808996f3.shtml

Hope this helps and best of luck!

Rob