Types of Registered Jacks (RJ45 & RJ11)
Introduction to Ethernet Jacks
Ethernet jacks are essential components in networking, providing a physical interface for data transmission over wired connections. The two most common types are RJ45 and RJ11, each serving distinct purposes in computer networking, telecommunications, and VoIP systems.
What is RJ45?
RJ45 (Registered Jack 45) is the standard connector for Ethernet networking. It supports 8 pins and is used with twisted-pair cables (Cat5e, Cat6, Cat7, Cat8) for high-speed data communication.
RJ45 Features & Applications
- Used in Ethernet networks (LANs, WANs, data centers).
- Supports Gigabit (1Gbps) and multi-gigabit speeds (10Gbps, 40Gbps).
- Compatible with shielded (STP) and unshielded (UTP) twisted-pair cables.
- Utilizes 8-position, 8-contact (8P8C) configuration.
- Found in network switches, routers, access points, and PCs.
RJ45 Pinout & Cable Color Codes
RJ45 connectors follow two wiring standards: T568A and T568B.
T568A Wiring Standard
| Pin | Cable Color | Purpose |
|---|---|---|
| 1 | White/Green | Transmit + |
| 2 | Green | Transmit - |
| 3 | White/Orange | Receive + |
| 4 | Blue | Unused (PoE Power) |
| 5 | White/Blue | Unused (PoE Power) |
| 6 | Orange | Receive - |
| 7 | White/Brown | Unused |
| 8 | Brown | Unused |
T568B Wiring Standard
| Pin | Cable Color | Purpose |
|---|---|---|
| 1 | White/Orange | Transmit + |
| 2 | Orange | Transmit - |
| 3 | White/Green | Receive + |
| 4 | Blue | Unused (PoE Power) |
| 5 | White/Blue | Unused (PoE Power) |
| 6 | Green | Receive - |
| 7 | White/Brown | Unused |
| 8 | Brown | Unused |
T568B is the most commonly used standard in modern Ethernet cabling.
What is RJ11?
RJ11 (Registered Jack 11) is primarily used in telecommunications for telephone lines and DSL broadband connections. It supports 6 positions and 2 to 4 contacts (6P2C or 6P4C configuration).
RJ11 Features & Applications
- Used for landline phones, DSL internet, fax machines.
- Supports analog voice transmission.
- Smaller than RJ45, only carrying one communication line.
- Can be inserted into an RJ45 port, but not vice versa.
RJ11 Pinout & Cable Color Codes
| Pin | Cable Color (2-Wire) | Cable Color (4-Wire) | Purpose |
|---|---|---|---|
| 1 | Not Used | Black | Additional Line (if present) |
| 2 | Not Used | Red | Additional Line (if present) |
| 3 | Green | Green | Tip (Primary Line - Positive) |
| 4 | Red | Yellow | Ring (Primary Line - Negative) |
| 5 | Not Used | Black | Additional Line (if present) |
| 6 | Not Used | Not Used | Unused |
Pins 3 and 4 (Red & Green) are the primary pair used in standard telephone connections.
Key Differences Between RJ45 and RJ11
| Feature | RJ45 | RJ11 |
|---|---|---|
| Size | Larger (8P8C) | Smaller (6P2C or 6P4C) |
| Pins | 8 | 2 to 4 |
| Use Case | Ethernet networking | Telephone & DSL |
| Cable Type | Cat5e, Cat6, Cat7, Cat8 | Telephone wire |
| Data Transmission | High-speed internet | Voice communication |
Conclusion
RJ45 and RJ11 connectors serve different purposes, with RJ45 dominating computer networking and RJ11 being used in telephony and DSL internet. Understanding their wiring standards and configurations ensures proper installation and functionality in both home and commercial environments.