RJ45 Plug Types
Jul 22, 2023
Leave a message
Regarding the question of RJ45 plugs types, many friends have been asking related questions, most of which arise during projects. Although it may seem simple, it is also the most common area for mistakes in projects. As for this issue, let's summarize and provide a comprehensive explanation of RJ45 plugs types, the functions of each core in twisted pair cables, all types of RJ45 plugs used for Cat 5, Cat 6, and Cat 7 cables, and address various questions related to the types of RJ45 plugs and their applications in twisted pair cables.
1. Wire Sequence and Transmission Distance
First, it is essential to understand the overall purpose of the eight copper conductors. The eight copper conductors are twisted together at a specific density to reduce mutual electromagnetic interference. This way, when transmitting electrical signals, the radiated waves between conductors cancel each other out, effectively eliminating interference. The name "twisted pair" is derived from this construction.
Twisted pair cables were initially used for transmitting telephone signals and were later gradually introduced into digital signal transmission. Nowadays, widely used are Cat5 and Cat6 twisted pair cables. Both Cat5 and Cat6 cables can achieve a bandwidth of 1000Mbps. However, Cat5 Cable has a shorter distance for transmitting gigabit signals. If using Cat5 for gigabit networks, it is recommended to control the distance within 30 meters.
One drawback of twisted pair cables is their limited transmission distance. Generally, they can reach up to 100 meters, while higher quality cables can achieve around 120 meters.
For typical gigabit networks, four pairs of wires (eight cores) are used. For networks below 100Mbps, usually, only four wires are used: 1, 2, 3, and 6.
Standard Line Sequence (T568B): Both ends of the line have the same sequence, which is: Orange-White, Orange, Green-White, Blue, Blue-White, Green, Brown-White, Brown.
The 568A line sequence is no longer necessary to remember, as it is no longer used.
2. Functions of Each Core
Why do twisted pair cables use 1, 2, 3, and 6 (1236) cores? That's because each core serves a specific function:
No 1. Output Data (+)
No 2. Output Data (-)
No 3. Input Data (+)
No 4. Reserved for telephone use
No 5. Reserved for telephone use
No 6 Input Data (-)
No 7 Reserved for telephone use
No 8. Reserved for telephone use
As we can see, although there are eight cores in twisted pair cables, in widely used 100Mbps networks, only four cores are actually used: 1, 2, 3, and 6, which respectively serve the functions of receiving and transmitting signals. Cores 4, 5, 7, and 8 are bi-directional and reserved for other uses.
However, in networks operating above 100Mbps, all eight cores are used. For example, for Category 6 or higher cables, not only cores 1, 2, 3, and 6 are used, but all eight cores are needed; otherwise, the network may become unstable.
In addition, there is a key factor: the transmission distance and stability of the cable are affected by the materials used. Some manufacturers may use pure copper for only four of the eight cores in the production of cables, while the other four cores may be made of copper-coated aluminum, copper-coated steel, or even copper-coated iron. Therefore, choosing reputable manufacturers (such as COBTEL) is crucial.
Inferior cables can suffer severe data transmission attenuation, resulting in significantly reduced transmission distances.
3. The Difference between Cat5e and Cat6 Plugs:
Now that we have understood the properties of twisted pair cables, let's focus on the differences between Cat5e plugs and Cat6 plugs. First, let's compare Cat5e and Cat6 cables.
Cat5e/Cat5:
Core diameter: 0.511mm
Cross-sectional area: 19.625mm²
Cat6:
Core diameter: 0.574mm
Cross-sectional area: 30.1754mm²
3.1 Cat5e Plug:
Front view of the Cat5e RJ45 plugs, showing all eight cores arranged in a straight line.
Side view of the Cat5e RJ45 plugs, indicating two teeth in the contact points.
3.2 Cat6 Plug:
The Cat6 RJ45 plug comes in one-piece and two-piece designs. Let's focus on the two-piece design.
The two-piece Cat6 RJ45 plug is different from the traditional Cat5e RJ45 plug as it consists of two parts: the internal divider and the outer shell.
Two-piece design (RJ45 plug and divider).
Front view of the Cat6 RJ45 plugs with all eight cores arranged in an interleaved pattern.
Cat6 RJ45 plug with three contact points for compression.
3.3 Termination method of Cat6 Plug:
Due to the characteristics of the Cat6 RJ45 plug, the wiring method also differs. It involves using an additional divider module.
Specific steps for terminating the Cat6 RJ45 plug:
Cat6 cables have all eight cores arranged in an up-and-down interleaved pattern, with larger wire slots. The front contact points have three forks, providing a larger contact area when compressing the cores. Cat6 RJ45 plugs are commonly used for gigabit networks and are also backward compatible with 100Mbps networks.
3.4 Can Cat6 Cables Use Cat5e RJ45 Plugs?
The copper cores of Cat6 cables are thicker than those of Cat5e cables. The difference in core thickness results in different hole sizes inside the RJ45 plugs. The entry hole for Cat5e is 1.02mm, while for Cat6, it is 1.08mm. If a Cat6 system uses Cat5e RJ45 plugs, it may cause poor near-end crosstalk (NEXT) and affect system performance.
Both types of RJ45 plugs have the same outer dimensions, so if it is a Cat5e system, Cat6 RJ45 plugs can be used for it.
4. What kind Of RJ45 Plugs are Used for Cat7 Cables? How to Make RJ45 Plugs?
4.1 Cat7 Plug:
As can be seen, the Cat7 plug has a metal shield casing. Cat7 cables adopt a single-pair shield and then an overall shield structure. Therefore, Cat7 RJ45 plugs are shielded, providing more effective elimination of crosstalk between pairs.
Cat7 cable
Cat7 plug
4.2 Termiantion of Cat7 Plugs:
Tools required: Cat7 RJ45 plug, wire stripper, scissors, crimping tool, cable tester.
For a more vivid understanding, we have provided a video to explain the process of making Cat7 plugs in detail.
4.3 Applications of Cat7 Cables:
Cat7 cables are generally used in scenarios that require high-speed transmission and high bandwidth, such as video conferencing, streaming media broadcasting, network-based voice calls, grid computing, and storage networks.
Due to their compatibility with 10/100/1000/10GBASE-TX Ethernet data transmission, they are also widely used in high-demand indoor horizontal cabling. Due to their strong shielding capabilities, Cat7 cables are suitable for shielded data centers and secure networks.
Due to their compatibility with 10/100/1000/10GBASE-TX Ethernet data transmission, they are also widely used in high-demand indoor horizontal cabling. Due to their strong shielding capabilities, Cat7 cables are suitable for shielded data centers and secure networks.
