This variable indicates the variety of DS1
Line implementing this circuit. The type of
circuit affects the number of bits per second
that the circuit can reasonably carry, as well
as the interpretation of the usage and error
statistics. The values, in sequence, describe:
TITLE: SPECIFICATION:
esf Extended SuperFrame DS1 (T1.107)
d4 AT&T D4 format DS1 (T1.107)