This page is part of the BART project.
Set B 500usec 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 500usec packet inter-arrival time for Set B.
Figures 30 to 33 show an interesting three-tier pattern produced by the time stamps. Again, statically setting the line speed to explicitly be 10Mbit/sec or 100Mbit/sec results in no improvement in time stamp performance.
Figure 30: Automatic 10Mbit/sec Figure 31: Explicit 10Mbit/sec Figure 32: Automatic 100Mbit/sec Figure 33: Explicit 100Mbit/sec
Tables 25 to 28 support the claim that there is no improvement in time stamp accuracy when the line speed of the inerface receiving the packets is explicitly set to 10Mbit/sec or 100Mbit/sec.
Table 25: Automatic 10Mbit/sec (usec)
Mean Varience Standard Deviation 583.21 30424.87 174.43
Table 26: Explicit 10Mbit/sec (usec)
Mean Varience Standard Deviation 583.21 30102.54 173.50
Table 27: Automatic 100Mbit/sec (usec)
Mean Varience Standard Deviation 508.32 25761.38 160.50
Table 28: Explicit 100Mbit/sec (usec)
Mean Varience Standard Deviation 508.31 24457.71 156.39
Last Updated: Tuesday 2-Dec-2003 09:46:42 AEDT URL: Maintained by: Ana Pavlicic email@example.com Authorised by: Grenville Armitage firstname.lastname@example.org