Final answer:
In a T1 circuit, approximately 1.544 Mbps is allocated for data transmission, while 64 Kbps is allocated for control information.
Step-by-step explanation:
In a T1 circuit, the bandwidth is allocated for both data transmission and control information. In this case, approximately 1.544 Mbps is allocated for data transmission, while 64 Kbps is allocated for control information.