The basics of Networking Devices

Question 1

Cables(1)

Answer 1

1 - Most network cables used today can be split into two categories: copper and fiber. Copper cables are the most common form of networking cable. They’re made up of multiple pairs of copper wires inside plastic insulator.
2 - The most common forms of copper twisted pair cables used in networking, are Cat 5, Cat 5e, and Cat 6 cables. These are all shorthand ways of saying category 5 or category 6 cables.
3 - Cat 5e cables have mostly replaced those older Cat 5 cables because their internals reduce crosstalk. Crosstalk is when an electrical pulse on one wire is accidentally detected on another wire.
4 - Cat 6 cables, following even more strict specification to avoid crosstalk, making those cables more expensive. Cat 6 cables can transfer data faster and more reliably than Cat 5e cables can, but because of their internal arrangement, they have a shorter maximum distance when used at higher speeds.
5 - Fiber cables contain individual optical fibers, which are tiny tubes made out of glass about the width of a human hair. These tubes of glass can transport beams of light. Unlike copper, which uses electrical voltages, fiber cables use pulses of light to represent the ones and zeros of the underlying data. Fiber is even sometimes used specifically in environments where there’s a lot of electromagnetic interference from outside sources because this can impact data being sent across copper wires.

Question 2

Cables(2)

Answer 2

4 - Cat 6 cables, following even more strict specification to avoid crosstalk, making those cables more expensive. Cat 6 cables can transfer data faster and more reliably than Cat 5e cables can, but because of their internal arrangement, they have a shorter maximum distance when used at higher speeds.
5 - Fiber cables contain individual optical fibers, which are tiny tubes made out of glass about the width of a human hair. These tubes of glass can transport beams of light. Unlike copper, which uses electrical voltages, fiber cables use pulses of light to represent the ones and zeros of the underlying data. Fiber is even sometimes used specifically in environments where there’s a lot of electromagnetic interference from outside sources because this can impact data being sent across copper wires.
6 - Fiber cables can generally transport data quicker than copper cables can, but they’re much more expensive and fragile. Fiber can also transport data over much longer distances than copper can without suffering potential data loss.

Question 3

Hubs and Switches

Answer 3

1 - Luckily, there are network devices that allow for many computers to communicate with each other. The most simple of these devices is a hub. A hub is a physical layer device that allows for connections from many computers at once.
2 - This causes a lot of noise on the network and creates what’s called a collision domain. A collision domain, is 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. This causes these systems to have to wait for a quiet period before they try sending their data again.
3 - A switch is very similar to a hub since you can connect many devices to it so they can communicate. The difference is that while a hub is a layer one or physical layer device, a switch is a layer two or data link device. This means that a switch can actually inspect the contents of the ethernet protocol data being sent around the network. Determine which system the data is intended for and then only send that data to that one system.
4 - This reduces or even completely eliminates the size of collision domains on the network.

Question 4

Routers(1)

Answer 4

1 - we often want to send or receive data to computers on other networks, this is where routers come into play. A router is a device that knows how to forward data between independent networks. While a hub is a layer 1 device and a switch is a layer 2 device, a router operates at layer 3, a network layer.
2 - Just like a switch can inspect Ethernet data to determine where to send things, a router can inspect IP data to determine where to send things. Routers store internal tables containing information about how to route traffic between lots of different networks all over the world. The most common type of router you’ll see is one for a home network or a small office.

Question 5

Router(2)

Answer 5

3 - The purpose of these routers is mainly just to take traffic originating from inside the home or office LAN and to forward it along to the ISP, or Internet service provider. Once traffic is at the ISP, a way more sophisticated type of router takes over. These core routers form the backbone of the Internet, and are directly responsible for how we send and receive data all over the Internet every single day.
4 - Core ISP routers don’t just handle a lot more traffic than a home or small office router, they also have to deal with much more complexity in making decisions about where to send traffic

Question 6

Servers and Clients

Answer 6

1 - A server, is as something that provides data to something requesting that data. The thing receiving the data, is referred to as a client.
2 - Most devices aren’t purely a server, or a client, almost all nodes are both at some point in time.
3 - in most network topographies, each node is primarily either a server, or a client. Sometimes we refer to an email server as an email server, even though it itself a client of a DNS server, why? Because its primary reason for existing, is to serve data to clients.