Quality of Networks

The quality of a network can only be measured in relation to the requirements of it’s users. If the users complain about poor network performance you need to prove their experience with the facts of network parameters. Afterwards you may find a strategy to improve the performance. To learn about the parameters of your network you need network supervision. Three data sources can be used for network supervision: Recording / collecting of SNMP Data from active network components Listening / sniffing to the network traffic of a segment Evaluation of NetFlow* data from switches or routers

The recorded data can often explain performance problems. Think about a running backup at the same time or the presence of a too high broadcast load, collisions or other network errors.

If only a single user complains while the rest of the network seems to work normally an end to end test can help find the problems.

NetQuality VoIP can be used to run such tests. During the tests you can try to adjust or change active network components – Maybe an older network adapter sticks to half-duplex, while the switch or hub wants to speaks full-duplex; it make sense to test with the affected device itself. Another device may not have the problem.

Some network problems may indicate that the used hubs or workgroup switches are losing frames under certain conditions. Besides viewing the syslogs of all involved devices a reconfiguration of the network and bypassing the defective device(s) may help and make things more visible.

Tracking down sporadic network quality problems often consumes much manpower. So take the best tools for this task you can effort.

*NetFlow is a registered trademark of Cisco Inc