HP 2424M - Manual (Page 33)

HP ProCurve Switch 4000M / 8000M / 2424M / 1600M Reviewer’s Guide
6.2.3 Latency Test - broadcast traffic
In this SmartApplications test a 64 byte broadcast packet is sent into port 1 of the switch. The FIFO 20
time it takes for the packet to emerge from the different ports is then recorded. The important
measurement here is the variability between ports.
6.2.3.1 100Mbps
64 byte broadcast packet
Port Latency 13 12.0µs
2 13.5µs 14 12.5µs
3 12.0µs 15 13.1µs
4 12.5µs 16 13.5µs
5 13.0µs 17 12.0µs
6 13.5µs 18 12.7µs
7 13.0µs 19 11.7µs
8 13.3µs 20 12.2µs
9 11.7µs 21 12.9µs
10 12.2µs 22 13.3µs
11 12.7µs 23 11.7µs
12 13.3µs 24 12.3µs
Mean: 12.63 (Calculated FIFO) 7.51 (Calculated LIFO)
Average Deviation: 0.54 (Calculated)
6.2.3.2 10Mbps
64 byte broadcast packet
Port Latency 13 86.7µs
2 89.4µs 14 87.3µs
3 87.7µs 15 87.6µs
4 88.4µs 16 88.2µs
5 89.0µs 17 86.9µs
6 89.5µs 18 87.6µs
7 89.1µs 19 86.3µs
8 89.1µs 20 87.0µs
9 87.9µs 21 87.4µs
10 88.0µs 22 88.2µs
11 88.6µs 23 86.6µs
12 89.5µs 24 87.2µs
Mean: 97.97 (Calculated FIFO) 36.77 (Calculated LIFO)
Average Deviation: 0.82 (Calculated)
20 See the Latency discussion in section 3 of this guide for details on FIFO versus LIFO figures.
©1998, 1999, 2000 Hewlett-Packard Co Revision 3.2b – 1/15/2000 Page 33 of 36