Lec-9: Types Of Cables in Computer Networks | Coaxial, twisted pair, fibre optic cable

Summary

In this video, the presenter explains various types of cables used in computer networks, focusing on Unshielded Twisted Pair (UTP), coaxial, and fiber optic cables. Key concepts covered include bandwidth (10 base T, 100 base T), attenuation (signal weakening over distance), and the physical layer of the OSI model. The video highlights the practical uses of these cables in Ethernet LANs, discussing their limitations like distance and data transmission rate. Viewers are also introduced to terms like collision domains and the importance of understanding how cables function in network communication, making it essential for exam preparation.

Takeaways

• 😀 Cables are used to connect devices in computer networks, facilitating data transmission.
• 😀 Unshielded Twisted Pair (UTP) cables are commonly used for Ethernet LANs, typically in 10Base-T or 100Base-T configurations.
• 😀 '10' in 10Base-T refers to a transmission rate of 10 Mbps (Megabits per second), which indicates the bandwidth of the cable.
• 😀 'Base' refers to Baseband signaling, where only one signal can be transmitted at a time through the cable, preventing simultaneous transmissions.
• 😀 'T' indicates the maximum length of the cable—100 meters for UTP cables, after which signal attenuation occurs, meaning the signal weakens.
• 😀 Coaxial cables also use electrical signals, with variants like 10Base-2 (200 meters) and 10Base-5 (500 meters), allowing longer signal distances than UTP cables.
• 😀 Fiber optic cables transmit data as light signals instead of electrical signals, allowing much higher transmission speeds (e.g., 100 Mbps at speeds of light).
• 😀 Fiber optic cables have a greater transmission distance, such as 2 km for 100Base-FX, compared to the limited distance of UTP or coaxial cables.
• 😀 Attenuation refers to the weakening of signal strength over distance, which is a common issue with UTP and coaxial cables after a certain length.
• 😀 In a network with multiple devices connected to a cable, collisions can occur when multiple devices attempt to send data simultaneously, leading to a collision domain.
• 😀 Cables do not filter data or check addresses like IP or MAC addresses; they are purely hardware components operating at the physical layer of the OSI model.

Q & A

What is the main purpose of the different types of cables in computer networks?

The main purpose of these cables is to connect various devices in a network and facilitate the transmission of data. Each type of cable has different properties, such as transmission speed and distance, which make them suitable for specific use cases in networking.

What does the term '10Base-T' refer to in the context of Unshielded Twisted Pair (UTP) cables?

'10Base-T' refers to a type of UTP cable with a bandwidth of 10Mbps. The '10' denotes the transmission speed (10 megabits per second), 'Base' refers to baseband signaling (only one signal can be transmitted at a time), and 'T' indicates a maximum distance of 100 meters for signal transmission.

What does 'Baseband' mean in cable terminology?

Baseband refers to a signaling method where only one signal is transmitted over the cable at a time. This means that at any given moment, only one device can send data, and if another device sends data at the same time, a collision will occur.

What is 'attenuation' in the context of data transmission, and why is it important?

Attenuation refers to the weakening of the signal as it travels over a cable. The signal loses strength after a certain distance, which limits the maximum transmission distance. For example, UTP cables experience attenuation beyond 100 meters.

What is the maximum transmission distance for a 10Base-T UTP cable?

The maximum transmission distance for a 10Base-T UTP cable is 100 meters. Beyond this distance, the signal weakens due to attenuation and can no longer be reliably transmitted.

How does the transmission speed differ between 10Base-T and 100Base-T cables?

The main difference is in the transmission speed. A 10Base-T cable has a transmission speed of 10Mbps, while a 100Base-T cable offers a much higher speed of 100Mbps, allowing data to be transmitted more quickly.

What is the significance of 'T' in cable specifications like '10Base-T' or '100Base-T'?

The 'T' in the cable specifications refers to the maximum distance the signal can travel. In the case of 10Base-T or 100Base-T, it indicates that the signal can travel up to 100 meters before it experiences attenuation.

What is the role of fiber optic cables in computer networks, and how do they differ from UTP cables?

Fiber optic cables use light signals rather than electrical signals, allowing for much higher speeds and longer transmission distances. For example, a 100Base-FX fiber optic cable can transmit at 100Mbps over distances of up to 2 kilometers, whereas UTP cables are limited to shorter distances and lower speeds.

What does 'Base' mean in fiber optic cable specifications like '100Base-FX'?

In fiber optic cable specifications, 'Base' refers to baseband signaling, which means that only one signal can be transmitted at a time, just like in UTP cables. 'FX' in 100Base-FX denotes a fiber optic connection with a maximum distance of 2 kilometers.

Can cables filter data, such as checking IP or MAC addresses?

No, cables cannot filter data. They are purely hardware and operate at the physical layer of the OSI model. Cables do not inspect data, IP addresses, or MAC addresses. They simply transmit data between devices without any form of filtering.