From Bell System Practice 359-200-100, issue 3, p. 27, as published in "CAPAR IV: L4-L5 Carrier", AT&T Long Lines, Eastern Area, 1977
From Bell System Practice 359-200-100, issue 3, p. 27, as published in "CAPAR IV: L4-L5 Carrier", AT&T Long Lines, Eastern Area, 1977