RJ45 Ethernet Cable vs RJ11 Telephone Cable: A Comprehensive Buying Guide

■ What Are RJ45 and RJ11?

The terms RJ45 and RJ11 refer to types of Registered Jack (RJ) connectors defined for telecommunications. These connectors vary in size, number of pins, and application.

• RJ45 Connector: This is the one most commonly used with Ethernet cables, and it has 8 pins and supports high-speed data transfer. It is the most widely used LAN connector.

• RJ11 Connector: Used in analog telephone lines, this is a smaller connector with 2 to 6 pins devoted to voice communication and DSL Internet applications.

⚠️ Important: RJ45 and RJ11 connectors were not intended to connect with each other; hence, make sure not to use the different one besides the cable type indicated on the device. Doing so may damage the equipment or affect the connections.

■ RJ45 Ethernet Cable: High-Speed Data Networking

Cable with RJ45 plug is most often used to connect computers, routers, switches, and other networking devices. It also covers categories such as Cat5e, Cat6, and Cat8 that form the remaining group with different levels of bandwidth and shielding.

Key Features:

• Connector Type: RJ45 (8P8C)

• Data Speeds: Transferring speeds up to 40 Gbps will be provided by the Cat8 cable.

• Frequency Range: This will be increased to 2000 MHz.

• Wiring Standard: Adhere to TIA/EIA-568-A/B.

• Usage: LANs, Data centers, and Industrial Automation.

Whenever you're looking for an Ethernet cable online or in the vicinity of your area, check to ensure that it complies with the router's or switch's speed specification (namely, use Cat6 for gigabit Ethernet).

■ RJ11 Telephone Cable: Create Connection for Voice Communication and Legacy Devices

RJ11 cables can be found almost everywhere in the connections of telephones, fax machines, and DSL modems. Due to their compact size and a small number of conductors present, they can be easily used for analog signals.

Key Features:

• Connector Type: RJ11 (6P2C, 6P4C, 6P6C).

• Data Speed: Reach a speed of up to 56 kbps (analog) and high speeds of up to 10 Mbps (Dsl).

• Frequency Range: 300 Hz – 3.4 kHz

• Usage: Telephone systems, modems, and intercoms.

Although similar in physical outlook, the RJ11 cord is still unsuitable for the high-speed data transfer of the modern internet. If you are weighing in on the telephone wire versus Ethernet connection, then the one that will benefit the user more is Ethernet as telephone lines are performance optimized only for verbal and not high-bandwidth data flow.

■ Phone Jack vs Ethernet Jack: Getting to Know the Physical Differences and Functional Differences

Such a situation occurs frequently. First, you try to insert a phone cable into the network port, and then you attempt to put it into the other way. Here are some physical and functional differences.

If you’re searching for an Ethernet cable near your location or online, ensure it matches your router’s or switch’s speed specification (e.g., Cat6 for gigabit Ethernet).

■ Phone Jack vs Ethernet Jack: Learn Physical and Function Differences

Disconnecting problems most frequently occurs when users attempt to insert either a telephone wire into a network port or vice versa. Let’s see the differences between those two jacks.

When you are installing a new system, putting in the Ethernet lines should take a priority because of their dependability. If you require older DSL lines for legacy applications, they can be added later, though.

■ Real-World Use Cases: Is it for RJ45 or RJ11?

■ Buyer’s Guide: How to Choose the Right Cable.

• Determine Your Device Port.

It’s also helpful to find out what port type the device has. Depending on the type of cable port, RJ11 is slightly smaller than RJ45. RJ11 ports are usually labeled “LINE” or “PHONE.”

• Check Bandwidth Needs.

For regular tasks such as file sharing, video conferences, or streaming, other Ethernet cables (normally with RJ45 connector) have the ability to provide wide bandwidth.

• Match the Cable Category.

It is a must to determine the cable category based on your network speed Requirements before using RJ45:

• Cat5e: Gigabit speeds (Uplink)

• Cat6: 10 Gigabit speeds (Very short distances)

• Cat7/Cat8: 10–40 Gbps (Very Short Shielded)

• Avoid Improper Conversions.

Disallow use of anything similar to an adapter; exact kinds (like RJ11 to RJ45 adapters) should only be used if part of genuine networking equipment such as VoIP gateways or DSL splitters.

■ FAQs: Ask the Questions.

Q1: Could you share the main distinction between telephone and Ethernet cabling?

Telephone cables (RJ11) carry voice signals, and Ethernet cables (RJ45) carry digital data signals for network connections.

Q2: Can I use RJ11 for Ethernet connections?

No, RJ11 cables for telecommunication have inadequate amount of pins or bandwidth to carry data connections on ethernet.

Q3: Are these RJ11 to phone jack converters real?

Only complete devices that have both RJ11 and RJ45 functions or with technology both will fully work. A physical piece of hardware without conduction signals will not serve the intended purpose.

Q4: Is it possible that certain designs of RJ11 plugs were deprecated?

However, some still use it for domestic landlines and just as well fewer use it for DSL service, but in the current world, with the advent of improved networking, the RJ45 Ethernet plug is the standard.

Q5: Does the telephone wiring be connected to the ethernet jack to bust it?

Yes. It may form a mismatch or a faulty connection (which may lead to permanent damage of the port).

■ Final Thoughts

With reference to RJ45 or RJ11, it all depends upon the particular application.

• Choose RJ45 Ethernet cables for transfer of data over LAN, networks, and use in smart apparatuses.

• On the other hand, RJ11 telephone cables are mostly used for analog phone communication and older models of gadgets.

So, if you want to understand the difference, make sure you know that a telephone wire is such a communication line is a LAN cable.

James is a technical manager and associate at Zion Communication. 

Specializes in Optical Fiber communications,  FTTH Solutions, 

Fiber optic cables,  ADSS cable, and ODN networks.

james@zion-communication.com

+86 13777460328