Modular connectors were originally used in the Registration Interface system, mandated by the Federal Communications Commission (FCC) in 1976 in which they became known as registered jacks. The registered jack specifications define the wiring patterns of the jacks, not the physical dimensions or geometry of the connectors of either gender. Instead, these latter aspects are covered by ISO standard 8877, first used in ISDN systems. TIA/EIA-568 is a standard for data circuits wired on modular connectors.
Other systems exist for assigning signals to modular connectors; physical interchangeability of plugs and jacks does not ensure interoperation, nor protection from electrical damage to circuits. For example, modular cables and connectors have been used to supply low-voltage AC or DC power and no clear standard exists for this application.
Nomenclature
Main article: Registered jack & Unofficial plug names
Modular connectors also go by the names “modular phone jack/plug”, “RJ connector” and “Western jack/plug”. The term “modular connector” arose from its original use in a novel system of cabling designed to make telephone equipment more modular. This includes the 4P4C handset connector.
It is very common to use a registered jack number to refer to the physical connector itself; for instance, the 8P8C modular connector type is often called RJ45 because the Registered Jack standard of that name was an early user of 8P8C modular connectors. A very popular use of 8P8C today is Ethernet over twisted pair, and that may be the most well known context in which the name RJ45 is known, even though it has nothing to do with the RJ45 standard. Likewise, the 4P4C connector is sometimes called RJ9 or RJ22 and various 6P connectors are called RJ11.
History
Modular connectors were originally developed and patented by General Cable Corp in 1974. They replaced the hard-wired connections on most Western Electric telephones around 1976. At the same time, they began to replace screw terminals and larger 3 and 4 pin telephone jacks in buildings.
Gender
Modular connectors have gender: male connectors are called plugs, while female connectors are called jacks or, sometimes, sockets.
Plugs are used to terminate loose cables and cords, while jacks are used for fixed locations on surfaces such as walls and panels, and on equipment. Other than telephone extension cables, cables with a modular plug on one end and a jack on the other are rare. Instead, cables are connected using a male-to-male adapter, which consists of two female jacks wired back-to-back.
8P8C
The 8 position 8 contact (8P8C) connector is a modular connector commonly used to terminate twisted pair and multi-conductor flat cable. These connectors are commonly used for Ethernet over twisted pair, registered jacks and other telephone applications, RS-232 serial using the EIA/TIA-561 and Yost standards, and other applications involving unshielded twisted pair, shielded twisted pair, and multiconductor flat cable.
Source: Wikipedia
Thanks Kevin.
As we only produce very small batches of devices, we are currently still using our first delivery of connectors. But as soon as our stock starts running low, I will contact you.