Channel, to be explained in the field of structured cabling, is the end-to-end cabling link from an active device, such as an Ethernet hub or switch, to the network interface of a personal computer, printer, fax machine, or other networked device. A part of the channel link is the Permanent Link. As the name implies, components used in permanent link are rarely changed, for they are usually hidden in the wall, up in the ceiling, or under the floor. And last, for connecting hardware, this simply refers to the component in the link that connects, such as keystone jacks, patch cords, or other connectors involved.
When it comes to performance, product guaranteed for channel performance simply means that it works well with specified components in the channel link. For Permanent Link, as there are less components involved, each component needs to have better performance to ensure the link will work well. The same explanation can be applied to Connecting Hardware performance. In another words, the shorter the link of the product which is guaranteed, the higher the performance is.
Per the TIA/EIA-568-C.2 series of standards, Channel performance and Permanent Link can be tested using FLUKE field testers, while Connecting Hardware testing requires a more precise Network Analyzer (NA). Listed by the strictness of the performance tests, the Connecting Hardware testing is the strictest set of tests, followed by the Permanent Link testing and then the Channel testing.