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Set A 1msec Packet Inter-Arrival Time
The following section discusses the difference between automatically allowing the interface to detect the line speed and explicitly setting the line speed of an interface for 1msec packet inter-arrival time for Set A.
As with the 125usec and 500usec inter-arrival time results, explicitly setting the line speed to 10Mbit/sec and 100Mbit/sec (and sending packets at these correct speeds from SmartBits2000) results in the time stamps of the packets being accurately closer to the theoretically ideal time stamp (inter-arrival time plus packet propagation time). The time stamps of the packets when the interface line speed was configured to auto-detect once again caused large variations that are not desired.
Figure 10: Automatic 10Mbit/sec Figure 11: Explicit 10Mbit/sec Figure 12: Automatic 100Mbit/sec Figure 13: Explicit 100Mbit/sec
We can see from the Table 9, 10, 11 and 12 mean values the additional packet propagation time of 83usec for the 10Mbit/sec line speed and 8.3usec for the 100Mbit/sec line speed.
Table 9: Automatic 10Mbit/sec (usec)
Mean Varience Standard Deviation 1083.21 16665.48 129.09
Table 10: explicit 10Mbit/sec (usec)
Mean Varience Standard Deviation 1083.21 1.09 1.04
Table 11: Automatic 100Mbit/sec (usec)
Mean Varience Standard Deviation 1008.33 17454.93 132.12
Table 12: Explicit 100Mbit/sec (usec)
Mean Varience Standard Deviation 1008.33 0.98 0.99
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