T Carrier Signaling and Framing

The total bandwidth of all DS-1 and higher circuits is higher than the sum of all of the channels, or 24 X 64,000, which equals 1,536,000. The total bandwidth of DS1 is 1,544,000 bps. On DS-1s, these extra 8,000 bits are used for signaling and framing. A frame is a grouping of bits with samples of user data from each of the 24 channels. Data from devices connected to the T-1 are samples 8,000 times per second, put into frames and sent sequentially on the T-1. Multiplexing on T-1 depends on strict adherence to timing - time division multiplexing.