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Primary Rate Interface 169
Figure 6-13
Sampling the Analog Wave
ESF is the assembly of 24 T1 frames. Each frame is still separated by a delineating bit, but not
all are used for framing. 2000 bps are used for framing, 2000 bps are used for CRC, and 4000
bps are used for data link control (this gives us many more management capabilities as
compared to SF). Figure 6-14 depicts a SuperFrame and an Extended SuperFrame.
Segment 2
Segment 1
Segment 0
Voltage
Time
8000
samples/sec
x 8
bits/sample
64000 bps
P
Se
Se
Se
St
St
St
St
1
0
0
1
0
1
0
1