Also found in: Dictionary, Thesaurus, Medical, Acronyms.


A serial connector which looks very much like a standard telephone connector, except it houses eight wires instead of four.

RJ-45s are typically found on computers either integrated into the mother board or on a NIC. Because they are so small they are often used on devices such as terminal servers that have many ports.

Ethernet (10baseT) and Token Ring sometimes use four wires of an RJ-45 plug, 100baseVG uses all eight. 100BaseTX uses the same four wires of the RJ-45 connector as 10baseT but the wire must be category 5 instead of category 3.


(Registered Jack-45) A common data networking interface that employs a cable of twisted wire pairs and an 8-pin modular jack. RJ-45 is used for Ethernet and Type 3 Token Ring networks. See cable categories and RJ-48.

RJ-45 Connectors
Eight-wire RJ-45 connectors are used with Ethernet and Type 3 Token Ring networks.

Variations of RJ-45
These are the variations of RJ-45 pins and wire colors.
References in periodicals archive ?
The linear Z-MAX termination module allows conductors to be laced quickly and naturally into position without pair crosses, maintaining and protecting cable pair geometry for optimized transmission performance consistency and removing a significant source of noise and interference present in all other RJ-45 outlets.
This black CAT5E VERICOM UTP 24 Port Patch Panel with back to back RJ-45 connectors is made of high quality black metal and includes blanks above each port for ease in labeling.
RJ-45 Connectors with Integrated Magnetics and LED Options Engineered for High-Component-Density Networking and Telecom Applications
A standard RJ-45 Ethernet connector mates the SEM inside the enclosure, simplifying installation, and all operate at +9 VDC to +24 VDC.
It has a built-in network connection with a RJ-45 LAN Connector for remote control and access by a Web browser for diagnostics as well as automatic e-mail of product status and a RS-232C connectivity for remote control.
The device also boasts five switched or routed RJ-45 10/100 Ethernet LAN ports, one simplex SC single strand bi-directional 100MB fiber port, two five REN RJ-11 VoIP-enabled POTS ports and a single coaxial port making it the most robust and flexible fiber-based residential gateway in its class.
The unit also integrates multiple Power-Over-Ethernet (POE) RJ-45 injector ports and Power with Serial (PwS) Connectors, so that clean isolated power and signal are carried over a single standard Ethernet or serial cable to connected devices.