| The IEEE and the TIA/EIA have established standards that
allow you to test whether your network is operating at an acceptable level. If your
network passes this test and is certified as meeting the standards, you can use this
measurement as an established baseline. The baseline is a record of your network's
starting point or newly installed performance capabilities. Knowing the baseline measurement is important. Testing does not end just because
your network installation is certified as meeting the standards. You should continue to
test your network on a regular basis in order to ensure that it performs at its peak. You
can do this by comparing current measurements with recorded measurements that were taken
when the system was known to be operating properly. If there is a significant change from
the baseline measurement, it is an indication that there is something wrong with the
network. Repeated testing of your network, and comparisons against its baseline, will help
you spot specific network problems that may be caused by aging, poor maintenance
practices, weather, or other factors.
One example of an all-purpose tool for
testing the baseline health of a network is shown in the figure. Fluke
Networks' NetTool (or other equivalent all-purpose handheld testers)
provides vision into the cause of desktop-to-network connectivity
problems, combining the capabilities of a network tester, a PC
configuration tester, and a basic cable tester. NetTool (or
equivalent) connects between the PC and the wall jack. Once connected,
the NetTool listens, collects, and organizes information regarding the
following:
- the network resources
available,
- the network resources the PC is
configured to use, and
- the health of the network segment -
including errors, collisions, utilization, and the health of the
PC NIC card and the local network.
You can also use NetTool (or
equivalent) to perform basic cable tests to detect opens, shorts,
split pairs, length to the open on any RJ45-terminated cable, and
pin-to-pin wiremap tests on installed wiring or patch cables.
Summary of NetTool's (or equivalent)
Capabilities:
- Service Identification: Identifies a
jack as Ethernet, Token-Ring, Telco or inactive.
- Link Reporting: Discovers and
reports the previously unseen the PC-hub/switch link negotiation.
- Inline Mode: concisely displays the
PC's IP address and network resources used: default router, email
server, DNS, and web servers accessed.
- Basic Cable Testing: Performs basic
cable tests, showing opens, shorts, split pairs, length, and
pin-to-pin wire mapping.
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