Understanding Ethernet Cable Categories and Network Setup
Ethernet Cable Categories
Category 3, 4, 5, and 5e
Category 5 offers the best benefits, including improved data transmission speeds.
Category 6
Category 6 provides a wide bandwidth, with a maximum of 1 Gbps at 250 MHz, suitable for demanding applications.
Category 7
Category 7 offers a maximum bandwidth of 600 MHz.
100Base T Features
- Maximum speed: 100 Mbps
- Maximum cable length: 100 meters
- Impedance: 100 ohms for unshielded cable and 50 ohms for shielded cable
100Base T refers to 100 Mbps, twisted pair, and baseband transmission. 100Base TX is used when employing UTP cable Category 5.
How to Make a Network Cable
- Cut the cable ends, remove the outer jacket, exposing the eight colored wires.
- Untwist the pairs and arrange the wires in the following order: white-orange, orange, white-green, blue, white-blue, green, white-brown, brown.
- Using a crimper, cut the wires evenly to ensure they reach the end of the connector.
- Place the connector with the chip facing down and verify the wire order is correct. Ensure the wires reach the end of the connector and the jacket is inside the connector’s groove for a secure grip.
- Crimp the connector using the crimper.
Creating a Crossover Cable
To connect two computers directly without a switch, use a crossover cable. The wiring sequence differs on one end of the cable.
- One end of the crossover cable should have the following sequence: White-Green, Green, White-Orange, Blue, White-Blue, Orange, White-Brown, Brown.
- The other end remains the same as a standard cable.
Hubs vs. Switches
Hubs
A hub is a central connection point for twisted pair cables in a star topology network. Hubs are characterized by the number of ports and supported speeds.
- Hubs broadcast information from one port to all others.
- All branches operate at the same speed.
Switches
A switch is an improved version of a hub.
- Switches forward Ethernet frames only through the necessary ports.
- Each port has a buffer to store frames.
- Switches can’t work with different speeds on their branches.
- Typically, switches have three LEDs per port: one indicating activity, another the speed, and the last one indicating a collision.
Switches use a switching table to determine the destination port. A processor analyzes the Ethernet frame’s destination address and searches for it in the table. If found, the frame is forwarded through the indicated port. If not found, the switch floods the frame to all ports, acting like a hub.
Ethernet frames contain a source address, which the switch uses to update its switching table, associating the address with the port it received the frame from. As network traffic increases, the switching table is built dynamically. To prevent outdated information, entries in the table have a Time To Live (TTL) expressed in seconds, after which they expire.