Networking

Group: Ian (1, 2, 3), Cristian (4, 5, 6), Saria (7, 8, 9, 10, 11), Alejandro (12)

1. What is a computer network?

A computer network is a group of computing systems that are linked together through a number of channels to communicate and share resources amongst a range of users. It’s a group of interconnected computers that can all talk to one another.

Source:

Janssen, Cory. “Computer Network.” Technopia. N.p., n.d. Web. 1 Nov. 2013. http://www.techopedia.com/definition/25597/computer-network.

2. Define and explain visually the difference between these different types of networks:

Local Area Network: A local area network covers a small area, like a home or office. It’s most likely based on Ethernet technology.

Wide Are Network: A network that covers a broad range of geographic area.

Internet: A global network that connects millions of computers, including over 100 countries.

Intranet: A limited communications network, sometimes a private network made from World Wide Web software.

Metropolitan Area Network: A network that connects two or more local area networks together but does not leave a town or city.

Virtual Private Network: A private network that uses a public network (the Internet) to connect users together. The virtual connections are routed through the Internet from the business’s private network to the employee.

Source:

a) “Computer Networks.” Contrib. N.p., n.d. Web. 1 Nov. 2013. http://www.contrib.andrew.cmu.edu/~sfaiadh/computer_networks.htm.

b) “Internet.” Webopedia. N.p., n.d. Web. 1 Nov. 2013. http://www.webopedia.com/TERM/I/Internet.html.

c) Tyson, Jeff, and Stephanie Crawford. “How VPNs Work.” How Stuff Works. N.p., n.d. Web. 1 Nov. 2013. http://www.howstuffworks.com/vpn.htm.

3. How do these two types of networks differ?

Peer to Peer: A network where two or more computers share resources without having to go through a separate server. Data is stored between computers and on multiple computers.

Server-based: In this kind of network, the server is the central base where users can access information and resources to share. Each computer that connects to the server is called a client computer.

Source:

Cope, James. “QuickStudy: Peer-to-Peer Network.” Computerworld. N.p., 8 Apr. 2002. Web. 1 Nov. 2013. http://www.computerworld.com/s/article/69883/Peer_to_Peer_Network.

4. What is the difference between a client and a server?

A client and a server are two parts of a common computing model. A user uses a computer (which is the client). The computer then sends requests to the server, which is usually located somewhere else remotely. The server takes the request and processes it, then sends back a response to the client.

Source:

“Difference Between Client and Server.” Difference Between. N.p., n.d. Web. 1 Nov. 2013. http://www.differencebetween.net/technology/difference-between-client-and-server/.

5. What is the OSI model?

The OSI model is a theoretical model that explains how networks work. It contains seven layers (physical layer, datalink layer, network layer, transport layer, session layer, presentation layer, and application layer.

Physical (Layer 1) – This layer outlines the physical characteristics of network devices, which includes cabling, wiring, and fibre strands. Transmission of data from the physical medium is managed at layer 1.

Datalink (Layer 2) – This layer has four primary functions: a) communication with the network layer above, b) segmentation of upper layer datagrams, c) bit ordering, and d) communication with the physical layer below.

Network (Layer 3) – This layer has the job of handling routing and preparing data for transmission.

Transport (Layer 4) – This layer has the responsibility of recovering lost or damaged data.

Session (Layer 5) – This layer tracks connections (sessions) and keeps track of multiple file downloads that are requested by an FTP application.

Presentation (Layer 6) – This layer takes the conversion of data and between platform independent formats to a format understood by the local machine.

Application (Layer 7) – This layer is the user interface. It shows data to people in a way they can understand.

Source:

InetDaemon. “What Is the OSI Model.” InetDaemon. N.p., 6 Mar. 2013. Web. 1 Nov. 2013. http://www.inetdaemon.com/tutorials/basic_concepts/network_models/osi_model/what_is_the_osi_model.shtml.

6. Identity 5 different network architectures, explain what each does.

Tiered architectures:

4 types:

One-tiered: This is when there is direct access from the client servers to the file server. This is a very efficient tier and it is very simple, but it is also not very secure.

Two-tiered: This is very similar to a one-tiered server but it is much more secure. It allows client servers to access certain ares of the file server when requested but does not have access too all information. This also allows multiple client servers to access it as long as they are accessing different parts of the file server.

Three-tiered of Multi-tiered: This adds another tier in-between the client and file server called the application server and this helps to organize the connection and control the high amount of traffic flow. This allows a lot of security and it allows the client server to have very fast access. The big problem with this is that it can be very expensive and complex.

Peer-to-Peer: This is when the peer server acts as both the client and the file server, and each is connected to each other. This is very simple and takes out any middle interfereance

Sources:

a) Janssen, Cory. “Peer-to-Peer Architecture (P2P Architecture).” Technopia. N.p., n.d. Web. 1 Nov. 2013. http://www.techopedia.com/definition/454/peer-to-peer-architecture-p2p-architecture.

b) Howitz, Carsten. “What Is 3-Tier(Multi-Tier) Architecture And Why Do You Need It?”Simcrest. N.p., 1 June 2012. Web. 1 Nov. 2013. http://blog.simcrest.com/what-is-3-tier-architecture-and-why-do-you-need-it/.

7. Define and visual explain what the following terms mean:

Protocols:
A protocol is a system used to transmit data (such as index files) in order to determine the type of error checking than needs to be used. It is also used for data compression (useful for communication) in order to determine how the device will indicate that a message has been sent. Protocols on your computer or device must be agreeable with the right ones if you need to communicate with other computers.

Source:

“Protocol.” Webopedia. N.p., n.d. Web. 1 Nov. 2013. http://www.webopedia.com/TERM/P/protocol.html.

TCP/IP (transmission control protocol/internet protocol):
It is the communication language of the protocol of the Internet used in the intranet or extranet. It is a two-layer program of which the first layer of the TCP manages a message into smaller packets that can be transmitted over the internet and received by another TCP layer that reassembles these smaller packets into the original message.

Source:

Rouse, Margaret. “TCP/IP (Transmission Control Protocol/Internet Protocol).” Search Networking. N.p., Oct. 2008. Web. 1 Nov. 2013. http://searchnetworking.techtarget.com/definition/TCP-IP.

FTP (file transfer protocol):
A standard protocol used for the transfer of files between different computers on the Internet. FTP works in the similar way as the HTTP as it is an application protocol that uses the Internet’s transmission control protocol to transfer Internet files to its server to make it available to everyone on the Internet. “Commonly used to download programs and other files to your own computer from a different server”.

Source:

Rouse, Margaret. “File Transfer Protocol (FTP).” Search Enterprise WAN. N.p., Apr. 2007. Web. 1 Nov. 2013. http://searchenterprisewan.techtarget.com/definition/File-Transfer-Protocol.

HTTP (Hypertext Transfer Protocol):
A protocol used by the World Wide Web. It defines how messages are transmitted and the actions that browsers should take in response to different commands. When a URL is entered into the browser, the HTTP is what directs the web server to transmit the requested web page.

Source:

“HTTP.” Webopedia. N.p., n.d. Web. 1 Nov. 2013. http://www.webopedia.com/TERM/H/HTTP.html.

Telnet:
It is a user initiated command used for accessing remote computers. With this underlying protocol is allows for the access of another user to enter someone else is computer remotely. With telnet you are able to log on as a “regular user with whatever privileges you may have been granted to the specific application and data on that computer”.

Source:

Rouse, Margaret. “Telnet.” Search Networking. N.p., Aug. 26. Web. 1 Nov. 2013. http://searchnetworking.techtarget.com/definition/Telnet.

8. What is a router?

A router is a small device that joins a number of different networks together and forwards data along these networks. It connects two or more networks that the router operates. Home networks use the Internet Protocol router. It is commonly connected to LANs or WANs. It is a critical device that keeps the networks connected to the Internet. Most Internet users use LAN (local area network) or a WLAN (wireless LAN) in order to connect all computers to the Internet without paying a broadband subscription.

Source:

a) Mitchell, Bradley. “Router.” About.com. N.p., n.d. Web. 1 Nov. 2013. http://compnetworking.about.com/cs/routers/g/bldef_router.htm.

b) Beal, Vangie. “All About Broadband/ICS Routers.” Webopedia. N.p., 28 Aug. 2009. Web. 1 Nov. 2013. http://www.webopedia.com/DidYouKnow/Hardware_Software/2005/router.asp.

9. What is a network firewall?

It is a software program used in order to protect your computer from unauthorized access. They could also be hardware devices. They guard the computer’s internal and private network from outside access. A firewall works closely with proxy servers that make network requests on behalf of users. These firewalls provide extra safety LAN addresses from the outside Internet. “They help screen out hackers, viruses, and worms that try to reach your computer over the Internet”. School students that are unable to access Facebook and social networks at school often use proxies.

a) Mitchell, Bradley. “Firewall.” About.com. N.p., n.d. Web. 1 Nov. 2013. http://compnetworking.about.com/od/firewalls/g/bldef_firewall.htm.

b) Rouse, Margaret. “Firewall.” Search Security. N.p., May 2007. Web. 1 Nov. 2013. http://searchsecurity.techtarget.com/definition/firewall.

c) “What Is a Firewall?” Microsoft. N.p., n.d. Web. 1 Nov. 2010. <http://www.microsoft.com/security/pc-security/firewalls-whatis.aspx&gt;.

10. What is the difference between a web and ftp server?

Web server: A server used in order to communicate with web browsers as it usually uses the HTTP communication protocol. The web server is able to transfer HTTP request but not actual files as with FTP. FTP (file transfer protocol) is what allows the transfer of files from one computer to another.

Source:

“What’s a Web Server? How Does a Web Server Work?” Geek Explains. N.p., n.d. Web. 1 Nov. 2013. http://geekexplains.blogspot.ca/2008/06/whats-web-server-how-does-web-server.html.

11. What is an IP address?

An IP address is an Internet protocol. It is designed to allow one computer to communicate with another via the Internet. It allows billions of users to be differentiated from other devices. “In the same sense that someone needs your mailing address to send you a letter, a remote computer needs your IP address to communicate with your computer.” They serve as a permanent Internet address in order to allow other computers to communicate with you. There are two different types of IP addresses. There are the static IP addresses and the Dynamic IP addresses. A static IP address is used for online gaming where users are able to communicate with other computers faster. They are less secure than Dynamic IP addresses because they are easier to track. Dynamic IP addresses are temporary and are assigned each time the computer accesses the Internet.

Source:

“What Is an IP Address?” What Is My IP Address. N.p., n.d. Web. 1 Nov. 2013. http://whatismyipaddress.com/ip-address.

12. How do you transfer files from a computer to a server? Create a small tutorial to teach us how to do it.

In order to transfer files from a computer to a server, several conditions have to apply first:

the server must be running– meaning that the server is connected to the internet, has space/memory to place files, and owns an IP addres.
the user has to have access to the internet– without access to the internet, then it is impossible to load files to the server unless it is a local server which only needs access to the router.

If these two conditions apply, then accessing the server is possible. There are different ways to place files in a server and it depends if it is a local or a far away server. What stays true though is that to access any of them you need an

  • IP address or host name
  • know the type of protocol being used (SFTP, FTP, FTPS, etc)
  • username
  • password

to access the server, generally the web browser is used but there are other softwares where it can grant you access like WinSCP (and variations of it for MAC and Linux). Anyway, using the web browser, the user has to put the URL/host name or IP address in the address bar to go to the server. Once there, it should ask for a username and password (which is set when installing the server). Once in you can change your password, and have access to all or some of the files there (depending on the user’s credentials). Now, the server has to have a button or a link that takes you to the uploading section of the page and make your transfers there.

I own a server, and I can access it locally too which is very convenient and faster. how this works is that your computer , since it is connected to the same router as the server, files can be transferred instantly, and without the hassle of going into the browser. Instead, the server folder appears on the explorer window (Windows), on the finder (mac) or on the nautilus (ubuntu/linux).

There is a third way. Only if the user has a software like Adobe Dreamweaver. If the server is used to store a website, then synchronizing the server with dreamweaver would be a great option since the software would take the data needed for the site. In the ‘Manage Sites’ panel, there is are several options. first the site has to be created into a root folder so that the website can have a firm location and source. then after the site is established, the user can go into the servers tab, and set up the server through the FTP (File Transfer Protocol) option. this way, the user inputs the address of the server, username and password, and the program does everything for you. the user will get two windows where he/she will see a nested list of folders inside the server in one, and another with the files in the computer. Once this is done, the user only has to drag the files from one location to another.

-one very important note- The file transfer speed for the computer to server and vice versa will be directly affected by the speed of the internet, so beware of large files. sometimes it is good to compress files before placing them in the server to make things faster and easier.

a) “Dendrome Project.” Dendrome Project. 01 Nov. 2013 http://dendrome.ucdavis.edu/help/faq/?faq_id=16.

b) “WinSCPFree SFTP, SCP and FTP client for Windows.” Connect to FTP server or SFTP server. 01 Nov. 2013
http://winscp.net/eng/docs/guide_connect.

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