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As the LAN environment gets increasingly complex , Tim Widdershoven of Ideal Networks issues some guidance to help technicians identify the source of errors more simply and get the most from their network troubleshooting tester .
Network transmission media can be copper , fibre or wireless so network technicians need to be armed with troubleshooting tools that can tackle any problem they encounter . This makes it more challenging for technicians if errors occur , these could be located in a wide range of different media and layers of the network .’
Here are six ‘ get of jail ’ solutions that technicians can use a tester to effectively troubleshoot errors .
Physical faults in network cabling
Most common network errors are at a physical level , such as problems with copper or fibre optic cabling , so this should always be the first place to start . For copper cabling , a network troubleshooting tester should be able to locate faults anywhere along a cable link using TDR ( time domain reflectometer ) technology to pinpoint distance to common faults . A tester that checks individual conductors in the cable versus checking only paired conductors reduces the time required to identify and repair the fault . Typically cable testers display wiremap faults as a pair even when only one conductor is at fault . When checking optical fibre , a tester that accepts common optical SFP ( small form pluggable ) modules allows the user to quickly determine whether the cabling or the network equipment is at fault .
Endpoint network testing
In this configuration the tester acts like any other device on the network , yet it has the capability to monitor and detect problems that may not be visible when using software troubleshooting tools . An essential part of identifying the source of errors is understanding the Ethernet network . This mode can verify that the network port to which the tester is connected has complete access to all network resources and can test for PoE ( Power over Ethernet ) when necessary .
In-line
Dual port testers can be inserted between any two points in the network allowing it to monitor all data passing through that point . The device can show the type of Ethernet connection at the two ports and identify speed mismatches as well as detect and identify the source of network errors . It can also be connected between the Internet router and the network to measure data transfer rate to the Internet . In-line mode features such as Top 10 lists can also help detect devices that are using a particularly large amount of bandwidth .
Network map
A network map feature provides an overview of all devices on a LAN . For troubleshooting , saving this map and returning to it later can show where changes to a network have occurred . For example , if a user can no longer access a particular server , the network map can show if the server is still accessible on the network . If the troubleshooting tester has an integrated trace-route function , faulty routers can be identified in large LANs and even across WAN ( wide area network ) environments .
VoIP
Diagnostic options for VoIP ( Voice over IP ) connections can also be helpful for troubleshooting . The tester can be connected between a VoIP telephone and the network , measuring call quality of service ( QoS ) metrics to confirm reported call quality issues and identify the problem .
Wi-Fi
Wi-Fi networks are particularly susceptible to problems and an access point ( AP ) can be the source of errors , although it appears to be working correctly . A nearby AP may be utilising the same channel , creating interference and reducing the range of the Wi-Fi network . Using the in-line capability , the tester can be connected between the AP and the network to monitor the combined traffic of all wireless devices . This may result in adding APs to increase bandwidth when demand exceeds the capacity of a single AP . In addition , the copper wire connecting the AP to the network could be faulty .
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