Cable Issues PDF

2.6.2 Cable Issues When troubleshooting cable connectivity, you are focusing on issues at the Physical layer. At layer 1, a typical Ethernet link for an office workstation includes the following components: Network transceiver in the host (end system). Pa...

2.6.2 Cable Issues When troubleshooting cable connectivity, you are focusing on issues at the Physical layer. At layer 1, a typical Ethernet link for an office workstation includes the following components: Network transceiver in the host (end system). Patch cable between the host and a wall port. Structured cable between the wall port and a patch panel (the permanent link). Patch cable between the patch panel port and a switch port. Network transceiver in the switch port. The entire cable path (patch cords plus permanent link) is referred to as a channel link. Verifying patch cord connections. (Image by Kjetil Kolbjornsrud © 123RF.com.) Assuming you are investigating link failure (complete loss of connectivity), the first step is to check that the patch cords are properly terminated and connected to the network ports. If you suspect a fault, substitute  the patch cord with a known good cable. If you cannot isolate the problem to the patch cords, test the transceivers. You can use a loopback tool to test for a bad port. If you don't have a loopback tool available, another approach is to substitute known working hosts (connect a different computer to the link or swap ports at the switch). This approach may have adverse impacts on the rest of the network, however, and issues such as port security may make it an unreliable method. If you can discount faulty patch cords and bad network ports/NICs, you will need to use tools to test the structured cabling. The solution may involve installing a new permanent link, but there could also be a termination or external interference problem. Copyright © The Computing Technology Industry Association, Inc. All rights reserved.