ESF

A T-carrier framing convention that extends the superframe sequence from 12 to 24 frames; with signaling performed in frames 6, 12, 18, and 24. ESF offers the advantages of non-disruptive error detection through a six-bit cyclic redundancy check (CRC), and an embedded operations channel (EOC) for network management. See also CRC, D1, D2, D4, D4, frame, network management, superframe, and T-carrier.