You can configure physical interfaces such as a T3 in Controller Configuration mode.
From Global Configuration mode, type the appropriate controller command and its attributes, and then press Enter.
host1(config)#controller t3 9/1 host1(config-controll)#
host1(config)#controller ? e1 Configure a channelized E1 controller e3 Configure a E3 controller sonet Configure a Sonet controller t1 Configure a channelized T1 controller t3 Configure a T3 controller