Explore CAT5, CAT6, CAT7, and CAT8 Network Cables

Explore CAT5, CAT6, CAT7, and CAT8 Network Cables
 

1. Building a Network Based on Coaxial Cable

The cross-section of different Ethernet cables reveals varying internal physical components. Nowadays, newer Ethernet cables are often tightly twisted and have more complex outer layers, while older cable types are becoming obsolete. So, how do different twisted pair Ethernet cable generations differ?

CAT3

CAT3 cables, although somewhat outdated, are still in use. With a maximum frequency support of 16 MHz, this Ethernet type can still be utilized for telephone lines and 10BASE-T networks. CAT3 cables can also be employed for alarm systems or similar applications. They may have 2, 3, or 4 twisted pairs (although not common). However, nowadays, CAT5e has become the most widely used Ethernet type due to its higher speed.

CAT5

CAT5 Ethernet, introduced as an Ethernet type with a data transmission speed of up to 10/100 Mbps over distances of up to 100 meters, also known as Fast Ethernet. Nowadays, CAT5 is considered outdated and has been replaced by CAT5e.

Speed of CAT5: 100 Mbps / 100m.

CAT 5e

Although CAT5 and CAT5e share physical similarities, Ethernet type 5e adheres to stricter IEEE standards. It is an enhanced version, meaning a version with better resistance to crosstalk.

CAT5e is the most common cable type due to its ability to support Gigabit speed at a reasonable cost. While both CAT5 and CAT5e support a maximum frequency of up to 100 MHz, CAT5e has completely replaced its predecessor. Gigabit Ethernet uses 4 data pairs, doubling Fast Ethernet. Moreover, CAT 5e also supports speeds up to 1000 Mbps. It can be used for both small and large spaces. Among all current cable types, CAT5e is the most cost-effective and efficient choice.

Speed: 100 - 250MHz / 1 Gbps / 100m.

CAT6

CAT6 cable systems can support up to 10 Gbps and frequencies up to 250 MHz. Unlike CAT5e with 1.5-2 twists per cm, CAT6 is wound tighter with 2 or more twists per cm (the exact number varies by manufacturer).

CAT6 cables also have a thicker jacket compared to CAT5e. While standard Ethernet supports distances up to 100 meters, CAT6 cables only support 37-55 meters (depending on crosstalk) when transmitting at 10 Gbps. Its thicker jacket protects against Near-End Crosstalk (NEXT) and Alien Crosstalk (AXT).

Although CAT6 and CAT6a offer higher performance speeds, many LANs still opt for CAT5e due to cost-effectiveness and support for Gigabit speed.

Speed: 250-500MHz / 10 Gbps / 100m.

Comparing CAT3, CAT5/5e, and CAT6/6A.

CAT6a

CAT6a supports a bandwidth frequency of up to 500 MHz, doubling the capacity of CAT6, and can also handle 10Gbps like CAT6. However, unlike CAT6, CAT6a can support 10 Gigabit Ethernet at 100 meters. CAT6a also has a thicker jacket to eliminate AXT and improve the signal-to-noise ratio (SNR). However, due to its thicker jacket, CAT6a is less flexible than CAT6 and is suitable mainly for industrial environments.

Speed: 250-500MHz / 10 Gbps / 100m.

CAT7

CAT7, also known as Class F, can support 10 Gbps, but lab tests have shown it can transmit up to 40 Gbps at a distance of 50 meters and even 100 Gbps at 15 meters. This cable system also supports frequencies up to 600 MHz.

Overall, CAT6a can perform similarly to CAT7 but at a lower cost. CAT7 is suitable for use in data centers and large enterprise networks.

Speed: 600MHz / 10Gbps / 100m (40Gbps at 50m and 100Gbps at 15m).

CAT8

CAT8 cable is still in the development stage and has not been approved. According to the 2016 Ethernet Alliance roadmap, it will be able to support 25GB and 40Gb Ethernet, with even faster transmission speeds up to 30 meters.

2. How to determine the type of cable to buy.

Before deciding which cable to purchase, consider answering the following questions:
+ Are you looking for buried cable with UV resistance?
+ Do you want the cable to be approximately 15 cm away from electrical lines?
+ Do you want the cable to be inside the wall?
+ Do you need fire-resistant cable?

Price differences between various types can range from 100 USD to 600 USD, depending on the type.

3. Why are cables twisted?

When telephone wires were initially deployed alongside electrical wires, Alexander Graham Bell, often credited with inventing the telephone, twisted pairs of cables to reduce crosstalk. The same technique is applied to Ethernet cables.

4. Differentiating between FTP and UTP network cables.

Twisted pair cable without much shielding is known as UTP, commonly used for general LAN networks. This cable includes a protective conductor coating, such as copper or polymer conductive wire, to reduce interference. On the other hand, shielded twisted pair cables, known as FTP, are specifically designed for higher-frequency network environments.

There are various types of shielded twisted pair cables with protective casings covering all 4 data pairs. To differentiate between network cable types, you can look at their codes; for example, U denotes unshielded twisted pair, F indicates a shielded casing, and S stands for braided casing.

+ TP: Twisted Pair
+ U: Unshielded
+ F: Shielded
+ S: Braided

5. Types of shielded Ethernet cables.

- F / UTP: This cable type features an additional aluminum shielding layer beneath the outer shielding. F / UTP is commonly used in Fast Ethernet deployments.

- S / UTP: This cable wraps a braided shielding layer around the twisted pairs.
- SF / UTP: This cable has a shielding layer around the twisted pairs, with a silver paper wrap to protect the pairs.
- S / FTP: This cable wraps a shielding layer around all 4 twisted pairs, and each pair is individually wrapped in silver paper.
- F / FTP: This cable shields all 4 twisted pairs and individually wraps each pair in silver paper.
- U / FTP: This cable only shields the twisted pairs inside.
- U / UTP: No outer shielding.

Additionally, to determine which network cable is currently recommended, you can refer to the article on which network's fiber optic cable is the best among FPT, VNPT, and Viettel.