The Basics of Networking Devices

Cables

Connect different devices to each other, allowing data to be transmitted over them

• Copper wire
• Fiber wire

Copper

The most common forms of copper twisted-pair cables used in networking are Cat5, Cat5e, and Cat6 cables.

Cat - Category

uses electrical voltage

Cat5e mostly replaced old Cat5 cables. Cat5e cables reduce crosstalk.

Crosstalk

When an electrical pulse on one wire is accidentally detected on another wire

When crosstalk happens, the data is lost. Protocols can deal with lost data by detecting it and asking to sent them again. However that takes time.

Cat6 is more reliable and faster but it's maximum length is quite short.

Fiber (Optic) Cables

Contain individual optical fibers, which are tiny tubes made out of glass about the width of a human hair

Uses pulses of light

Specifically used in environments where electromagnetic interferences are high.

Fiber transports data much faster than copper but it costs more and is more fragile.

Fiber can transport more further than copper.

Data Centers use more fiber cables.

Hubs and Switches

16:26

Hub

A physical layer device that allows for connections from many computers at once

Collision Domain

A network segment where only one device can communicate at a time. If multiple systems try sending data at the same time, the electrical pulses sent across the cable can interfere with each other.

Switch - Network Switch

When hub is a Level 1 device, switch is a Level 2 device.

Routers

18:55

Hubs and switches

The primary devices used to connect computers on a single network, usually referred to as a LAN, or Local Area Network.

Router

A device that knows the way to forward the data between independent networks

Level 3 device.

ISA - Internet Service Provider

Broader Gateway Protocol (BGP)

Routers share data with each other via this protocol, which lets them learn about the most optimal paths to forward traffic.

Servers and Clients

21:08

There is a word Node. Node means some kind of spot inside of internet universe. Node can be a Server or a Client. What we call "Server" can be "Client" at some point of time. But we use the word "Server" to refer to a primary purpose of various nodes on a network.