RJ45 vs SFP

As a network engineer, RJ45 ports and SFP ports are often encountered. This article will introduce you to RJ45 and SFP.

What is RJ45

The RJ45 port is the most common network device interface, commonly known as “RJ connector”, and the technical term is RJ-45 connector.

“RJ” is short for Registered Jack – meaning “registered socket.” As defined in the FCC, RJ is the interface that describes the public telecommunications network. Commonly used RJ-11 and RJ-45 are.

“45” is the number of the interface standard.

RJ45 usually connects one end to an Ethernet cable and is used to connect various network devices such as computers, routers, switches, etc. The RJ45 port is an 8-position 8-contact (8P8C) modular plug and jack, 8P means 8 slots and 8C means 8 gold-plated contacts for Ethernet-based local area networks (LANs).

Cables with RJ45 connectors on both ends are called RJ45 Ethernet cables. Cat5, Cat6, and Cat7 cables are the most commonly used RJ45 cables in network connectivity today.

Wire sequence connection

The twisted pair cable can be connected to the RJ45 port in two modes: T568A and T568B. These two standards define how the RJ45 pinout arranges eight individual wires when connecting the RJ45 connector to the cable. These wiring layouts have their own color conventions for electrical compatibility. The T568B wiring scheme is considered to be a more common one.

Wire sequence of the T568A

1 White-Green, 2 Green, 3 White-Orange, 4 Blue, 5 White-Blue, 6 Orange, 7 White-Brown, 8 Brown

Wire sequence of the T568B

1 White-Orange, 2 Orange, 3 White-Green, 4 Blue, 5 White-Blue, 6 Green, 7 White-Brown, 8 Brown

What is SFP

SFP ports, also known as mini-GBIC ports, have a transmission rate of 1 Gbit/s and can support copper or optical links. When an electrical module is inserted into an SFP port, an Ethernet cable (Cat5, Cat5e, or Cat6) is usually used to connect the electrical module to the SFP port for data transmission. When an optical module is inserted into an SFP port, optical fibers are required for longer transmission. The SFP port is used for signal conversion and data transmission. It complies with the IEEE 802.3ab standard.

The SFP ports are flexible and hot-swappable. They support both electrical and optical modules. In addition, the SFP ports are backward compatible and support 10/100/1000 Mbit/s.

RJ45 vs SFP

If you have any questions, please feel free to contact csd@telecomate.com