The Permanent Link is the cable that is fixed within the fabric of the building. It normally includes the distribution patch panel, horizontal cable and work area outlet/consolidation point but does not include the patch cords or any link between the consolidation point and the work area outlet.
The Channel includes all of the elements of the cabling system over which the data is transmitted, including the patch cords, consolidation point links and cross connect patch panels.
The Permanent Link has the benefit that it is easy to re-test at any time in the future because nothing within this element of the cabling infrastructure should have changed since it was installed. This means that a direct comparison can be made between the performance of the cabling at any given time and the performance at the time of original installation. On the other hand, each time a patch cord or consolidation point link is changed then the configuration and performance of the Channel is changed and it is not possible to directly compare the test results between the two different configurations.
If a problem with data transmission on a particular Channel is experienced then it is important to first test the Permanent Link. This will highlight if there are any problems with the fixed cabling. The Channel should then be tested to see if the issue lies with the patch cords or other cabling elements.
It is important to remember that the patch cords are an integral part of the cabling infrastructure and that they have a direct effect on the performance of the Channel and, therefore, its ability to support the desired data transmission rates. Compromising on the quality of patch cords used will ultimately compromise the quality of data transmission.