CH06 - Telecommunications and networking

Question 1

What’s the definition of a computer network?

Answer 1

A system that connects computers and other devices via communications media so that data and information can be transmitted among them

Question 2

What are the 4 types of enterprise network?

Answer 2

• PANS
• LAN
• WAN
• MANS

Question 3

What is a PAN?

Answer 3

A Short-range network (typically few meters)

Question 4

What is a LAN?

Answer 4

A network Limited geographical region coverage – Your apartment building, for example

LANs are embedded meaning that they are connected to the backbone WAN in an enterprise environment.

Question 5

What is a WAN?

Answer 5

A network with Larger area coverage. (The internet)

Question 6

What is a MAN?

Answer 6

A relatively large network (Metro-politan area networks)

Question 7

What is a MAN?

Answer 7

A relatively large network (Metro-politan area networks)

Question 8

What’s a backbone network?

Answer 8

High-speed central networks to which multiple smaller networks (e.g., LANs and smaller WANs) connect.

→ To connect them physically together we use Network interface card (See image)

Question 9

What’s a server?

Answer 9

It is a dedicated computer to assure the functionality of your network

Question 10

What’s the bandwidth

Answer 10

It is the transmission capacity of a network (bits/second).

Question 11

What’s a broadband?

Answer 11

The transmission capacity of a communications medium that is faster than 50 Mbps.

Question 12

What’s the Ethernet?

Answer 12

It’s a common area network protocol

Question 13

What are the 2 network fundamentals?

Answer 13

1. Network Protocols
2. Types of Network Processing

Question 14

What is a network protocol?

Answer 14

• Devices/nodes on a network that transmit and receive data.
• They work together by adhering to a common set of rules and procedures (protocol)
• Protocols enable devices to communicate with one another.

Question 15

What are the 2 major network protocols?

Answer 15

1. Ethernet protocol
2. Transmission Control Protocol / Internet Protocol.

Question 16

What’s an Ethernet protocol?

Answer 16

• A common LAN protocol
• Sets a way to connect computers
• The 400-gigabit Ethernet is the latest standard for high-speed network communications based on Ethernet protocol.

Question 17

What’s a Transmission control protocol (TCP)?

Answer 17

• manages the movement of data packets between computers by establishing a connection between the computers
• sequences the transfer of packets
• acknowledges the packets that have been transmitted.

A file transfer protocol that can send large files of information across sometimes unreliable networks with the assurance that the data will arrive uncorrupted.

Question 18

What’s the Internet Protocol (IP)?

Answer 18

A set of rules responsible for disassembling, delivering, and reassembling packets over the Internet.

→ Works with TCP

Question 19

What’s packet switching?

Answer 19

The transmission technology that divides blocks of text into packets.

1. Before data are transmitted over the Internet, they are divided into small, fixed bundles called packets.
2. Single message is broken into multiple message blocks
3. Each message block containing addressing info (IP address) to indicate point of origin and final destination.
4. Packet-switching networks are reliable and fault tolerant. ** **IMPORTANT
5. If a path in the network is very busy or broken, packets can be dynamically (“on the fly”) rerouted around that path. Also, if one or more packets do not get to the receiving computer, then only those packets need to be resent.

Question 20

What is a packet?

Answer 20

a packet is a small segment of a larger message. Data sent over computer networks*, such as the Internet, is divided into packets. These packets are then recombined by the computer or device that receives them.

• The packets use the TCP/IP protocol to carry their data.

Question 21

The 4 Layers of TCP/IP (IMPORTANT)

Answer 21

• Application layer enables client application programs to access other layers. It defines the protocols that applications use to exchange data (HTTP, SMPT)

→ Hypertext Transfer Protocol (HTTP), which defines how messages are formu- lated and how they are interpreted by their receivers.

• Transport layer provides the application layer with communication and packet services. (TCP)
• Internet layer is responsible for addressing, routing, and packaging data packets. (IP protocol)
• Network interface layer places packets on, and receives them from, the network medium.

Question 22

What are the Network Processing types?

Answer 22

Client-Server

Peer-to-peer (P2P) (Ex: a Google doc)

Question 23

Peer-to-peer (P2P) network processing can be divided into 3 types

Answer 23

1. Processing sharing: this type accesses unused CPU power among networked computers. (e.g., SETI@home)
2. Real-time person-to-person collaboration (e.g., MS SharePoint a platform not installed on your computer but accessed through a browser)
3. Advanced search and file sharing (e.g., bittorrent.com, VOIP SKYPE)

Question 24

What is the Internet?

Answer 24

• The way computers connect to each other
• Short for inter-network
• A global system which use TCP/IP protocol suite to connect various electronic devices.
• A huge collection of interconnecting devices
• The network of the networks
• Includes different networks like public, private, academic, government and others.

Question 25

MORE on the Internet, important facts to understand it

Answer 25

* No central agency manages the Internet * The Internet is designed to be redundant and fault-tolerant—meaning that if one network, connecting wire, or server stops working, everything else should keep on running. * Internet backbone is a fiber-optic network that is operated primarily by large telecommunications companies. * A physical network connected on land under the ocean with largest data transmission line made of fiber optic trunk lines. * Nationwide infrastructure and ISP

Question 26

What's is the Internet architecture?

Answer 26

the physical infrastructure through which Internet service providers (ISPs) exchange Internet traffic between their networks.

Question 27

What are the components of the Internet architecture?

Answer 27

* **Network Access Points** (NAPS) - Designated locations where many other different high-level networks can connect to the vBNS. (Very high-speed backbone network services) * **NAP**: Exchange points for Internet traffic * "**Network Access Point**" is of **historical interest** only, since the four transitional NAPs disappeared long ago, replaced by modern **Internet Exchange Points** (IXPs) * **Internet Service Providers** (ISP) - Infrastructure provider

Question 28

What's Canada's Internet backbone?

Answer 28

FIBER OPTIC

Question 29

What's Fiber Optic?

Answer 29

**It consists of thousands of very thin filaments of glass fibres that transmit information through pulses of light generated by lasers**. The fibre- optic cable is surrounded by cladding, a coating that prevents the light from leaking out of the fibre.

Question 30

Other **Communications Media and Channels (Backbones)**

Answer 30

* Twisted-pair wire * Coaxial Cable * Fiber optic

Question 31

What are the networks that use Internet protocols?

Answer 31

* Intranet * Extranet

Question 32

What's Intranet?

Answer 32

* A private network that uses TCP/IP protocols. * Intranets support discovery , communication, and collaboration inside an organization.

Question 33

What's Extranet?

Answer 33

* A network that connects parts of the intranets of different organizations. * It enables business partners to communicate securely over the Internet using VPNs. * Extranets offer limited accessibility to the intranets of participating companies.

Question 34

What are IP addresses?

Answer 34

An **IP address** is comprised of a network number (routing prefix) and a rest field (host identifier). * Each computer on the Internet has an assigned address, IP address. * Numerical – a series of numbers * Denotes a specific host and the network attached to the Internet * 135.62.128.91

Question 35

What are the two IP addressing schemes?

Answer 35

* IPv4 (32 bits) * IPv6 (128 bits) → REMEMBER uncountable number of possibilities for IPv6 vs. a lot for IPv4

Question 36

What are the components of an IP address?

Answer 36

* A rest field is an identifier that is specific to a given host or network interface. * A routing prefix is often expressed using Classless Inter-Domain Routing (CIDR) notation for both IPv4 and IPV6. * **City,** **Zip code** and **area code** are also included in the IP address, a certain numerical combination represent a certain zip code etc**.**

Question 37

Domaine names

Answer 37

A name related to an IP address easier to remember (Ex: for a customer)

Question 38

What's Domaine Name System (DNS)?

Answer 38

* DNS like the Internet's phonebook! * You can actually type an IP address of a website into a Web browser, and that page will show up. But that doesn’t help users much because four sets of numbers are really hard to remember * DNS is a distributed database that looks up the host and domain names that you enter and returns the actual IP address for the computer that you want to communicate with. * DNS is a distributed, fault-tolerant system that uses nameservers to map host/domain name combinations to IP addresses.

Question 39

What's the World Wide Web (WWW)?

Answer 39

A system of universally accepted standards for storing, retrieving, formatting, and displaying information via a client/server architecture. The network accessible information. → \*\*\* It is not the INTERNET \*\*\*

Question 40

What are browsers?

Answer 40

* Software applications through which users primarily access the Web. * Web page: a file written in HyperText Markup Language

Question 41

What's Hypertext?

Answer 41

It is the underlying concept defining the structure of the World Wide Web. Hypertext is the text displayed on a computer display or other electronic device with references, called *hyperlinks,* to other text that the reader can immediately access, or where text can be revealed progressively at additional levels of details

Question 42

What's HTML?

Answer 42

web pages are developed using html

Question 43

What's Uniform Resource Locator (URL)?

Answer 43

It's the web address **(SEE IMAGE REALLY HELPFUL)** ## Footnote For example, the URL for Microsoft is **http://www.microsoft.com**. Recall that HTTP stands for *hypertext transport protocol.* The remain- ing letters in this URL—**www.microsoft.com**—indicate the domain name that identifies the web server that stores the website.