1000BASE-T/100BASE-TX/10BASE-T Physical Layer Compliance Tests Manual
Intel Confidential
109
Worst-Case Cable for Jitter
Table C-1. Constructed Jitter Test Cable Segments Lengths
Cable Segment / Type
Meters
Feet
Inches
Notes
L1 (constructed cable)
1.20
3.94
47.24
3 feet, 11.24 inches
L2 (quality CAT5 cable)
117.7
386.15
4633.85
386 feet, 1.85 inches
L3 (constructed cable)
1.48
4.86
58.27
4 feet, 10.27 inches
TOTAL CABLE
120.38
Table C-2. Constructed Jitter Test Cable Delay Specifications
Delay
Cable Type
4.75 nsec/meter
Quality CAT5 cable
4.673935 nsec/meter
Constructed cable
10.8 nsec
Constructed cable segments L1 and L3 (L1 + L3 = 1.20 + 1.48 = 2.68 meters)
559.2 nsec
Quality CAT5 cable of segment L2.
(117.72632 meters of standard CAT5 cable is required for a 559.2 nsec
delay.)
Table C-3. Average Insertion Loss Comparison
16 MHz
31.25 MHz
50 MHz
80 MHz
100 MHz
Quality CAT5 cable of 120 meters
8.61
12.22
15.62
20.08
22.73
Quality CAT5 cable of 117.7 meters
8.44
11.99
15.32
19.7
22.29
Constructed cable of 2.68 meters
0.18
0.24
0.33
0.48
0.46
Total Insertion Loss of
117.7 m quality CAT5 cable +
2.68 m constructed cable
8.62
12.23
15.65
20.18
22.76
IEEE specification maximum
Insertion Loss
9.13
12.98
16.64
21.33
24
Table C-4. Constructed Jitter Test Cable Average Insertion Loss per 9.9062 Meters
16 MHz
31.25 MHz
50 MHz
80 MHz
100 MHz
rb
0.6333
0.8905
1.1827
1.632
1.6982
vg
0.6695
0.9165
1.262
1.9602
1.7455
blbr
0.6674
0.8969
1.1465
1.8189
1.6671
gw
0.6896
0.8907
1.219
1.7077
1.7382
Average
0.66
0.90
1.20
1.78
1.71