What Distinguish between a link and a channel in multiplexing?

Link refers to the physical path and channel refers to the portion of a link that carries a transmission between a given pair of lines. One link can have many (n) channels.

The permanent link includes only that portion of the cabling installation that is "permanent" (think punched down). It includes jack to rack -or- wall outlet to patch panel. One connector is allowed at each end but any patch cables must be accounted for and removed from the test results. This generally means you must use the cables that came with your test equipment so the equipment knows exactly what to subtract.

The channel link includes two or more patch cables and may include multiple patch panels - possibly in multiple closets.

By: ISRAFIL CSE