Permanent link vs. channel

When testing structured cabling, two basic topologies are used:
Permanent link—the connection from a patch panel to a work-area telecommunication outlet (i.e. also called horizontal cabling). This is the most permanent fixture in structured cabling and cannot be easily taken apart. The maximum permitted length is 90 m.
Channel—the connection from an active device (e.g. a switch) in a data rack to a network card, patch cords included. The recommended maximum length of equipment cords in data racks is 5 m; the maximum recommended length for work area cords is 20 m. The length of the channel (i.e. the horizontal cabling plus an equipment cord as well as a work-area cord) should not exceed 100 m..