Lab log # 8

The Digital Divide

The gap, caused by students/children that have access to the internet at home and the ones that do not, is called the digital divide. As today's society further advances to being more dependant on computers, those who do not have a computer are left in the dust. Many teachers at school assign homework that can only be completed by using many different resources. Students that have internet can easily pull up these resources at home and complete their homework quickly and with ease. The students that do not have this advantage have to stay after school, or go in a t lunch to use the school computers or books. This can cause an issue as it is cutting into a part of the students time that they would rather not be spending doing homework, while other students can go hang out and then complete their assignment late in the night if need be.

The lack of internet at home also effects the level of in-depthness of the an assignment or project as the student has less time to work on it and therefore rushes through it. This can greatly affect a students learning in comparision to their fellow classmates. Students that have to rush through their work do not have time to absorb the information or comprehend it and instead just hand in their paper hoping that they will get a decent mark. Students that do not use the internet regularily can't efficiently manuever about the web with the same proficiency than the students that do. This causes them to get their assignments done later and not to be as involved as they could be.

Students that do not have readily available usage of the internet do not know many of the dangers they face on the web daily. They do not know about the dangers of clicking into pop-up ads or how to stay clear of sites/offers that are not legitimate. These students will read something and automatically beleive that the information is correct when it could just be any old drivel that someone had posted.

Schools are now starting to make sure that there is an acceptable amount of computers available to the students to work on projects, and have teachers that can explain how to mauever through the sites easier. At LVR for instance they are starting to replace the old out-of-date computer and putting in new ones. They have a library, computer lab, and homework help room that allow students with access to the internet. In the community, the municipal library has computers that can be used for research on any possible subject.

I beleive as a person that uses the internet quite frequently, that it is unfortunate that so many are denied the quick and easy access to so much wonderful resources that are available at just the click of a mouse. It really is amazing to see how much the internet has changed the lifes people live in the past couple years. I think that the communitiy should try to provide more access to computers to further aid these students that are internet deprived. Or that teachers should provide more class time for internet-based porjects so students do not have to rush throught hem as much. I also beleive that people who don't have the internet need to figure out alternate was of getting access to the internet. By either going to a friends, asking a friend, taking the time to stay at school; they could finish their assignments quickly and with a higher degree of excellence if they so choose.

My sources
Myself
Breeanne
mother
bryton

Module B Assignment # 7

The subject/sentence that I chose to research was: How do chlorofluorocarbons effect the stratosphere.



1- Google



Google found 190, 000 hits in the time period of 0.27 seconds for this search. It quickly identified the key terms and used them to find the sites best suited for my search. Google indexes it's searches in a library list format. Webpages that have the most of the important terms stated in your search appear closer to the top of your results page list. The webpages that have little or no relevance on the otherhand are placed further down the list, usually several pages from the first. Google rates it pages by putting the pages that contain the precise sentence you wrote down or words that you searched, or the pages that contains the biggest number of words of which you searched. Many pages appear on the list due to what is known as word hits. This meaning that the word(s) you searched are randomly being found on these sites. Another reason that irrelevant sites will appear near the top of you results list is because they are sponsored. This means that the site owner has paid google to have their site appear near the top of your search, even if your search has nothing to do with the site. For some searches, links appear at the top of the page boxed in yellow. These are known as sponsored links and the only thing they do is get in the way of your search. These "sponsored links have little to do with your search and generally involve buying their product.



2- AllTheWeb



A total of 328,000 hits in a short time period appeared for this search. It quickly identified the key terms and used them to find the sites that it beleived were best suited for my search. Many of the sites shown on the page had little to do with the actual concept I was researching. Despite this the AllTheWeb has good features. The search engine allows you to specify your search to certain areas, such as audio, video, and image. This allows for a more accurate results on your search. Its indexing is done the same way as Google does, in the library list format. In comparison AllTheWeb has a site that looks more professional, and newer than that of Google's home page. The pages that appeared near the top of the page had very less relevance to the search than that of the sites pulled up on Google. The advertising on the page goes straight to the page ahead. A site owner dcan pay for their page to be at the "top of the list".



3- Yahoo



Yahoo found 337, 000 hots in a time period of 0.36 secs. While typing in my search into the search box it provided several similar searches that had been recently been searched on the same subject. This I think is a useful feature because if you are doing a research project it would help you to find the best pages. Yahoo also indexes it's searches in a library search format. The site finds the best possible match for your search putting the sites with either the exact statement you searched or the most word hits. It then places these more relevant sites ate the top of the page for easier access. Yahoo filters out alot of the pages that have little importance to the search. The short blurb that comes with the site's link is helpful and tells you exactly what you can expect to find on the page. Unlike Google, Yahoo does its advertising differently. The difference is that instead of the ads being placed at the top of the page, the sponsors are placed in a column that runs the length of the right side of the screen. This allows you to do your search with out them being immediately in the way.

Google, which is one of the most used search engines known, ended up showing the least amount of hits. Despite being helpful, it wasn't as helpful as the yahoo search engine. The yahoo search engine came up with a significantly bigger number of hits than Google and it filtered out the less relevant sites so as to avoid frusteration by going to those such sites. Yahoo overall was more reliable, fast, convienient and had the most amount of hits.

I think that Yahoo was the best choice as it provided quick, reliable service and helped me to find the information that I needed instead of sites with little relevance. The filter feature was definetly very helpful.

Lab Log # 7

LEO' s or Low Earth orbiting satellites can often be found in satellite consellations. One of these such satellites covers a very small area, and cover higher angular velocities so as to maintain its orbit. Since the area that is being covered by these LEO satellites is small many are needed to maintain continuous coverage. These such satellites are deployed into satellite constellations. An example of this kind of constellation that a LEO often travels in is a GPS. These GPS's allow people to find their way from one point to another when driving, hiking, or boating somewhere new and don't know the turrain.

MEO's or Medium Earth Orbiting satellites ornit in the area between 100 and 1000 miles above the Earth's surface. These satellites are farther away from the earth than a LEO satellite, but still lower than a GEO satellite. Unlike the LEO satellites quick orbits, the MEO satellite can take any where from 2 to 12 hours to complete its orbit around the Earth. The speed and altitude remain constant throughout its orbit, as its orbit ensures that by being a perfect circle.
Earth based transmitters that have low frequencies are able to reach these satellites. Using several MEO satellites it is possible to have global wireless communication. In comparision to the LEO satellites coverage, it would take seven LEO satellites to cover the distance that one MEO satellite can cover. An example of something that uses the MEO satellites are cellular phones, as they provide communication on a global scale.

GEO's or Geosynchronour Earth Orbiting satellites are the satellites that pass points on the Earht constantly on a regular basis. A GEO satellite that is found over the equator is known as a geostationary satellite. GEO satellites are generally stationed over parts of the equator, for transmitting and receiving of antennas on Earth that will work without tracking satellites. One example of an antenna that a GEO is responsible for revolving are ones that involve weather forecasting, global communication, and television broadcasting. Though GEO satellites are useful they also have their faults. Due to the huge distance that the GEO satellites are away from the Earth, radio signals take a quarter of a second to reach the satellite and return to the Earth. These radio signals could possibly interfer with the Earth's telecommunication, thus making it harder for people to communicate with one another.

Module B Assignment # 6

WLANs

Wireless Local Area Networks and Security

Possible Problems

1) In vendor products the sercurity features are frequently not enabled.

2) Authentication is not enabled instead only simple SSID indentification occurs.

3) Cryptographic keys are short.

4) Cryptographic keys are not updated automatically and therefore not frequently.

Solutions to Above Problems

1- When security features are shipped they are not always enabled. Therefore all that is required to fix this problem is by enabling the security features or buy a better security system.

2- By setting up user accounts with passwords, so there is only the specified users that can access the network.

3- By having a larger key it lowers the chance of a brute-force attack. Generally keys should be 80 bits in length.

4- By changing your keys frequently it lowers the chance of being subject to a brute-force attack.

Bibliography

http://www.networkdictionary.com/wireless/WLANSecurity.php

http://www.webopedia.com

http://en.wikipedia.org

Lab Log # 5

Part A:
IP address . . . . . . . . . . . . . : 146.26.70.180
Subnet Mask . . . . . . . . . : 255.255.254.0
Default Gateway . . . . . . . . . : 142.26.70.1

IP address: location of a computer on a network in relativity to the network and the rest of the world.

Subnet Mask: location of the computer on a network

Default Gateway: a node (aka a router) on a computer network that serves as an access point to another network

Part B:

Interface: 142.26.70.180 on Interface 0x1000002
Internet Address Physical Address Type
142.26.70.2 00-14-22-75-ed-Oc dynamic
142.26.70.142 00-90-27-ac-30-fa dynamic

Internet Address: refer to the above definition of Ip address

Interface: a point of interconnection between a terminal and a network or between two networks

Physical Address: Also known as a real address or a binary address. It is the memory address that is electronically presented on the computer address bus circuitry in order to enable the data bus to access a particular storage cell of main memory.

Dynamic Type: A system that defines how a programming language classifies values and expressions into types. This is how it can manipulate those types and how they interact. A type indicates a set of values that have the same sort of generic meaning or intended purpose.

Bibliography:
http://en.wikipedia.wiki/Interface
http://en.wikipedia.wiki/Type_system
http://en.wikipedia.wiki/Physical_address

Assignment 5B

1. IEEE: Also known as the Institute of Electrical and Elcectronics Engineers. It is an international non-profit, professional organization that works on the advancement of technology related to electricity.

2. IEEE 802.3: Several IEEE standards that define the physical layer, as well as the media access control (MAC) sublayerof the data link layer, of wired Ethernet. Various types of copper or fiber cable make physical connections between nodes and/or infrastructure devices such as hubs, switches and routers.

3. Ethernet: It defines several wiring and signaling standards for the physical layer,though network access at the Media Acess Control(MAC)/Dataa Link Layer, and a common addressing format. It has a series of frame-based computer networking technologies for local area networks (LANs).

4. Star Topology: Consists of one central switch, hub or computer, that transmits messages to the other parts o the network. It is one of the most common co puter network topologies.

5. Hub: A device for connecting many twisted pair or fiber optic Ethernet devices together. This making them act as a sigle segment. These such hubs work at the physical layer of the OSI model. They are also responsible for forwarding a jam signal to all ports if it detects a collision.

6. Proxy Server: A porxy server is a server, in computer networks, which serves the requests of its clients by forwarding requests to other servers. The proxy server connects to a specifieed server and requests the service needed on behalf of the client.

7. Collision: in networking, it is when more than one computers or networking devices attempt to send data at the same time to one computer, server or other network device.

8.Firewall: It is a system that protects networks from unauthorized users and viruses, and can be used in hardware and/or software. Firewall can also control the amount of datat that leaves a network.

9. Protocol: It enables/controls the connection, communication and data transfer between two computing systems. It can also be referred to as a set of rules for communication. It can be used for both software and hardware, or both togethe. A protocol defines the behavior of a hardware connection.

10. Broadcast Domain: It is a logical network segment which in any devices connected to a netwrok can transmit directly to any other on the domain without having to go through a routing device. This is provided that they share the same subnet address and are in the same VLAN, default or installed.

11. Intranet: A private computer network that uses Internet protocols, and network connectivity to securelt share part of an organization 's information or operations with its fellow members. The term sometimes only refers to the most visible part of the service, the intranet website.

12. NIC: Stands for netwrok interface card. It is a piece of computer hardware that is designed to allow computers to communicate over a computer network. It is a device that works on the physical layer and the data link layer. This is due to the fact that it provides physical access to a netwroking medium and provides a low-level addressing system through the use of MAC addresses. It allows uses to conect to each other weither by using cables or wirelessly.

13.Router: It is a device that extracts a packet's destination that it receies, and then selects the best path for it to get to that destination. Therefore it forwards the data packets to the next device along this best chosen path. They are used to connect networks together so as to be able to connect to the internet.

14. Router: It is a device that attaches to the end-points of a bus network or daisy chain. It's purpose is to absorb signals so that they do not reflect back down the line. Ethernet netwroks and SCSI chains are some examples of things that require a terminator.

15. Plenum Cable: They are placed in the plenum spaces of a building. It is astiffer and stronger cable than a network cable.

16. Block coding: It is a type of channel coding that adds to a message so that the receiver can decode it with a minimual amount of error.

17.Plenum:It is the space in a bulding that is used for heating, ventillating, or airconditioning equiptment. This space is also where plenum cables are placed.

18. MAC Address: In computing networking it is a quasi-unique identifier attached to most network adapters (NIC). it is a number that acts as name for a particular network adapter.

19. Bridge: Filters data at a network boundary. It connects multiple network segments at the data link layer. Bridges are like repeaters or network hubs, as they connect network segments at the physical layer. Te difference between these devices is that the bridge manages data rather than just rebroadcast it.

20. Point To Point Technology: When information is transferred from one point to another.

21.Late Collision: A type of collision that occurs in CSMA/CD protocol standard. If the collision error happens after the initial 512 bits of data are transmitted, then the collicion is considered to be a late collision. More importantly, late collisions are not re-sent by the NIC, but instead left for the upper layers of the upper layers of the protocol stack to determine that the there was a loss of data.

22. MAU (Multiple Access Unit): is a device that attaches multiple network stations in a satar topology in a token ring network. It is internally wired to conect the stations into a logical ring.

23. Full Duplex Operation: Allows data to be sent both directions simultaneously in a connection between two devices. Full-duplex channels can be constructed either as a pair of simplex links or using one channel designed to permit bidirectional simultaneous transmissions. This sort of connection can only connect two devices, so many of these links are needed if multiple devices are attached together.

24. Half-Duplex Operation: Is capable of sending information in both directions between two nodes, but only one direction or the other can be utilized at a time. Any device in a conventional Ethernet networks, any device can transmit, but only one may dp so at a time.

25. Baud: It is a measure of the symbol rate, thenumber of distinct symbol changes made to the transmission medium per second in a digitally modulated signal.

26. Bit Rate: The number of bits that are processed or conveyed in a unit of time. It can be related to netwrokiung through the speed of the network , and how many bits are processed per second.

27. Link Integrity Test: MAUs continously monitor the receive data path for activity as a means of checking that the link is working properly. When the network is idle, the MAUs also send a link test signal to one another to verify link integrity. There are link lights at each end that are lit. This is important as it shows that there is a properly wired signal path between both devices.

28. 10Base (Generic): The most commonly used number system.Each number has a base of 10. It is also known as the decimal numeral system.

29. 100Base (generic): It is when a fast ethernet is going at 100Mbits/s.

30. LLC (library link code): It is the codes that a library puts on its website for people to have easier access to other links quickly.

31. AUI: Also known as an Attachment Unit Interface. It is a 15 pin connection that provides a path between a node's Ethernet interface and the MAU, alos known as a transceiver.

32. Packet: Discreet blocks of data. Data is seperated into these 'packets' so that instead of all the data that is being tranfered being corrupted and having to resend all the data again. Instead the packet that was corrupted or misplaced can be resent.

33. Bandwidth: It is the difference between the upper and lowercutoff frequencies of filters, a communication channel, ora signal spectrum, for a few examples. It is typically measured in hertz. Digital bandwidth refers to the data transfer rate measured in bits/s.

34. Repeater: Is an electronic device that receives a signal and retransmits it at a higher level or a higher power. It can also be retransmitted onto the other side of an obstruction, so that the signal can cover a longer distance without degradation.

35. Octet: A group of eight bits, often referred to as a byte. They are often used in networks.

36. Port: In the TCP and UDP protocols is a special number that is present in the header of a data packet. They are mainly used to mapdata to a particular process running o a computer.

37. Transmission Control Protocol (TCP): Is one of the core protocols of the Internet protocol suite. TCP gives reliable. in-order delivery of a stream of bytes, making it suitable for applications like file transfer and e-mail.

38. Internet Protocol (IP): It is a data-oriented protocol used for communicating data across a packet-switched internetwork. IP is a network layer protocol that can be found in the Internet protocol suite and is encapsulated in a data link layer protocol. IP provides the service oc communicable unique global addressing amongst computers.

39. File Transfer Protocol (FTP): It is used to transfer to transfer data from one computer to another through a network or over the internet. It is most commonly used protocol for exchanging files over netwoks that support the TCP/IP protocol. In this tranfer there is two computers the server and the client. The server listens on the network for connection requests from other computers. The client computerindicates a connection to the server. Once they are connected the client can do many file manipulation operations such as uploading and downloading files.

40. Logical address: It is a logical address which a memory location appears to reside from the perspective of an executing application program.

41. Domain Name Service (DNS): It is associated with various kinds of information with si-called domain names; but more importantly it serves as a phone book for the Internet by translating human-readable host names into IP addresses, that networking equiptment needs to deliver information. This system is an essential component of contemporary Internet use.


Bibliography

http://en.wikipedia.org/wiki/Bandwidth

http://en.wikipedia.org/wiki/Block_code

http://en.wikipedia.org/wiki/Broadcast_Domain

http://en.wikipedia.org/wiki/Ethernet http://en.wikipedia.org/wiki/Ethernet_hub

http://en.wikipedia.org/wiki/IEEE http://en.wikipedia.org/wiki/IEEE_802.3

http://en.wikipedia.org/wiki/Internet_Protocol http://en.wikipedia.org/wiki/Intranet

http://en.wikipedia.org/wiki/Late_collision http://en.wikipedia.org/wiki/MAC_address

http://en.wikipedia/wiki/network_bridge

http://en.wikipedia.org/wiki/Logical_address http://en.wikipedia.org/wiki/Network_card

http://en.wikipedia.org/wiki/Octet http://en.wikipedia.org/wiki/Plenum_cable

http://en.wikipedia.org/wiki/Protocol_(computing)

http://en.wikipedia.org/wiki/Proxy_server http://en.wikipedia.org/wiki/Repeater

http://en.wikipedia.org/wiki/Router

http://en.wikipedia.org/wiki/Star _network

http://en.wikipedia.org/wiki/TCP_and_UDP_port

http://en.wikipedia.org/wiki/Transmission_Control_Protocol

http://www.computerhope.com/jargon/c/collisio.htm

http://www.intel.com/products/glossary/body.htm

http://www.ethermanage.com/ethernet/10quickref/ch5qr_6.html

http://www.tcpipguide.com/free/t_SimplexFullDuplexandHalfDuplexOperation.htm

http://www.webopedia.com/TERM/T/terminator.html

Module B - Assignment 4

OSI is a model that defines a networking framework for implementing protocols in seven layers. Control is passed from layer to layer starting at the application layer (layer 7) and working its way down to the physical layer (layer 1). Then going to the next station over the channel and back up the layers.

The initial layer is the seventh layer, which is known as the application layer. This layer supports application and end-user processes. Everything at this layer is application-specific. The communication partners, any constraits on data syntax, as well as the quality of service are identified. While the user authentication and privacy are considered. Provided by htis layer are application services for file transfers, e-mail, as well as other software services. Some applications that entirely exist on this layer are Telnet and FTP. Also tierd application architectures are part of this layer.

The next layer is the sixth layer, which is known as the presentation layer. Less frequently it is also known as the syntax layer. Provided by this layer is the independence from differences in data representation. An example of thjis is encryption. This occurs by translating from network to application format, and vice versa. This layer works to transform data into a form that will be accepted by the apllication layer. This layer formats as well as encrypts data so that it can be sent across a network. This providing freedom from compatibility problems.

The fixth layer is known as the session layer. It establishes, manages and terminates connections between applications. Also it sets up, terminates and coordinates exchanges, conversations and dialogues between the applications at each end. This layer deals with the coordination of sessions and connections.

The fourth layer is known as the transport layer. It provides the transparent tranferring of data between end systems (or hosts), and is also responsible for end-to-end error recovery and flow control. This layer primary function is to ensure the complete transfer of data.

The third layer is known as the network layer. It provides switching and routing technologies, creating logical paths. These paths are known as virtual circuits, and are used for transmitting data from node to node. Functions of this layer include routing and forwarding as well as addressing, internetworking, congestion control, error handling, and packet sequencing.

The second layer is known as the data link layer. This layer encodes and decodeds data packets into bits. This llayer is divided into two sublayers: the Media Access Control (MAC) layer and the Logical Link Control (LLC) layer. How a computer on the network gains access to the data and obtaining permission to transmit it is controlled by thre MAC sublayer. The LLC layer, on the other hand, controls frame synchronization, flow control and error checking.

The final layer is the first layer which is physical layer. It is responsible for conveying the bit stream (electrical impulse, light or radio signal) through the network at the electrical and mechanical level. Provided by it is also the hardware means of sending and receiving data on a carrier. This including defining cables, cards as well as physical aspects. Protocols of this layer's components include Fast Ethernet, RS232 and ATM.

The relevance of the ethernet to OSI is as follows, it defines a number of wiring and signalling standards for the physical layer (the first layer). This occurs through means of network access at the sublayer MAC/Data Link layer (the second layer) and also through a common addressing format.

Bibliography

http://en.wikipedia.org/wiki/Ethernet

http://en.wikipedia.org/wiki/Open_Systems_Interconnection
http://www.webopedia.com/quick_ref/OSI_Layers.asp