t1 slotFramed E1 T1 with no. of Time Slots greater than or equal 4 -> Payload = 2 x no. of time slots. Unframed T1, C11 –> Payload = 48 (2 x 24 (all slots)). Unframed E1, C12 –> Payload = 64The first time slot is numbered 1. For a T1 controller, the time slot range is from 1 to 24. For an E1 controller, the time slot range is from 1 to 31. unframed—Unframed mode