|
assignment in the syllabus (Monday around midnight.) No credit will be given for late turn-ins.
Part 1
Answer the following: (3 points): Open the link for “1”, which is chapter 1, to the right of “Select Chapter” What links are available on the left side, besides: PowerPoint’s, and Text Book Images? Open up “animations”, and view “Packet Traveling Through Layers” In one or two sentences, indicate your impression of the animation? It’s an animation that shows one computer sending data to another computer on a network. It also shows the set layers that the data must travel thru. On the first computer you see the data traveling downward thru the layers then out to the physical network and then 2nd computer reverses the process unpacking it.
Part 2 Write out the question number, the question itself (this will greatly help you when you review for a test), and then your answer.
(A) Chapter 1, page 15, complete questions 3, 4, 5, 8, 11, and 12 1.3 According to the text it is possible to develop Internet apps w/o understanding the architecture of the Internet and technologies as long as the “programmer masters the interface; no further knowledge of networking is needed”. However, “a programmer who understands the underlying network mechanisms and technologies can write network apps that are more reliable, correct and efficient.”
1.4 data communications refers to the study of low-level mechanisms and technologies used to send information across a physical communication medium, such as a wire, radio wave, or light beam. 1.5 Packet switching is a communications paradigm that divides data into small blocks, called packets, and includes an identification of the intended recipient in each packet.
1.8 A communication protocol specifies the details for one aspect of computer communication, including actions to be taken when errors or unexpected situations arise. A given protocol can specify low-level details, such as the voltage and signals to be used, or high-level items, such as the format of messages that application programs exchange.
1.11 List the layers in the TCP/IP model, and give a brief explanation of each. Layer 1: Physical Physical layer specifies details about the underlying transmission medium and the associated hardware. • Specifies o electrical properties o radio frequencies, and signals Layer 2: Network Interface This layer specifies details about communication Between higher layers of protocols • Specifies o network addresses o maximum packet size that a network can support o protocols used to access the underlying medium, and hardware addressing belong in layer 2
Layer 3: Internet Layer 3 is the fundamental basis layer for the Internet it specifies communication between two computers across the Internet • Specifies o The Internet addressing structure o format of Internet packets o method for dividing a large Internet packet into smaller packets for o mechanisms for reporting errors belong in layer 3. Layer 4: Transport Protocols in the Transport layer provide for communication from an application program on one computer to an application program on another. • Specifies o maximum rate a receiver can accept data o mechanisms to avoid network congestion o techniques to insure that all data is received in the correct order Layer 5: Application Is the top layer of the TCP/IP stack specify how a pair of applications interact when they communicate. • Specifies o details about the format and meaning of messages that applications can exchange as well as procedures to be followed during communication. § Examples • email exchange • file transfer • web browsing • telephone services • and video teleconferencing 1.12 A header is additional information that is added by a protocol. In each layer each layer of protocol software performs computations that insure the messages arrive as expected. The sending computer prepends this extra information (header) onto the packet; the corresponding protocol layer on the receiving computer removes and uses the extra information.
Additional questions: Public networks have public IP address meaning that anyone can connect to the network by paying a subscription fee (internet service providers). A private network is controlled by a particular group. Private networks have private IP addresses and are not accessible to those outside the network.
What does it mean when two entities interoperate? Interoperation is when two entities can communicate without any misunderstanding. Chapter 2 2.6 The transition in graphics started in the 1990’s with the transfer of images, then by the late 1990’s video clips, and even full motion videos became conceivable, and today we have the ability to watch HD movies and shows and even 3D steaming in the near future. 2.7 It started with alert sounds and shifted to human voice then audio clips became available. By the late 1990’s video clips were able to be transmitted and downloaded and high quality multimedia content as well as high-fidelity audio became typical. 2.9 Analog systems have switched to digital and are now implementing the use of V.O.IP 2.10 Because with wireless technology we now have the ability to get low latency, high speed internet, in places where a hard line in not feasible, or cost efficient. I have benefited |
|
from this technology personally because I live in a rural area and before a descent WISP moved in we used satellite and it was horrible. Access into and explore the following web site. It contains information related to the growth of the Internet. Open the World Stats tab and view the information. Open the America Stats tab and view the information. In both cases you can view charts (scroll down first). http://www.internetworldstats.com/emarketing.htm
As a percent, which world region has the most users? (Look at the charts) (1 point) North America Scroll down and locate and open the Web Browser Statistics link. What two browsers are most widely used? 1 point Firefox and Internet Explorer Scroll farther down - Under Internet Usage Reports: What are the top 3 languages used on the Internet? (1 point) English, Chinese, and Spanish |
|
Either do Part 1 (a), or part 1 (b). (a). The client is calling the server and then the server accepts. And now they are ready to send and receive info between each other Part 2 (A) Chapter 3 3.1 What are the two basic communication paradigms used in the Internet? Stream & Message paradigms 3.3 Give six characteristics of Internet message communication. Connectionless Many-to-many communications Sequence of individual messages Messeges restricted to 64k Used for multimedia apps Built on UDP protocol 3.5 If a sender wants to have copies of each data block being sent to three recipients, which Paradigm should the sender choose? Message because it can handle 1 to many 3.6 What are the three surprising aspects of the Internet’s message delivery semantics? Messages can be lost, duplicated or received out of order. 3.7 Give the general algorithm that a connection-oriented system uses. Purpose: Interaction over a connection-oriented mechanism Method: A pair of applications requests a connection The pair uses the connection to exchange data 3) The pair requests that the connection be terminated 3.8 When two applications communicate over the Internet, which one is the server? The server is the application that starts first, doesn’t need to know which client will contact it, waits for a client to contact it, communicates by sending and receiving data, and stays running after client terminates. 3.11 Can data flow from a client to a server? Explain. Yes although it typically goes from the client sending a request and the server returning a response other relations are possible. 3.14 What two identifiers are used to specify a particular server? The IP address for the computer and the protocol port number that the service is on. 3.24 Why is symbolic constant INADDR_ANY used? It allows the server to operate on a multi-home host by allowing a server to specify port number while allowing contact at any of the computer’s IPs
(B) Chapter 4, pages 80 – 81 4.1 What details does an application protocol specify? The syntax and semantics of messages that can be exchanged Whether the client or server in it initiates interaction Actions to be taken if an error arises How the two sides know when to terminate communication 4.3 What are the two key aspects of application protocols, and what does each include? Representation and transfer Data Representation: Syntax of data items that are exchanged Specific form used during transfer Translation of integers, and characters, and files between computers Data Transfer: Interaction between client and server Message syntax and semantics Valid and invalid exchange error handling Termination of interaction 4.6 What are the four parts of a URL, and what punctuation is used to separate the parts? Protocol followed by a “://” then computer_name followed by “/” then document_name followed by “%” parameters 4.9 What does a browser cache, and why is caching used? Images such as (GIF’s) & (JPEG’s) and its used to load frequently visited webpage’s faster by storing the images. 4.12 When a user requests an FTP directory listing, how many TCP connections are formed? Explain. Ftp uses 2 TCP connections one for control commands (control connection) and one for actual data (data connection) 4.16 List the three types of protocols used with email, and describe each. SMTP: Is the standard protocol that a mail program uses to send mail over the internet
4.20 What are the two main email access protocols? POP3,IMAP 4.22 What is the overall purpose of the Domain Name System? Maps readable names to computer addresses 4.24 True or false: a web server must have a domain name that begins with www. Explain. False, because www is merely a convention for humans. 4.25 True or false: a multi-national company can choose to divide its domain name hierarchy in such a way that the company has a domain name server in Europe, one in Asia, and one in North America. True
Extra questions: Access into the following Web site. http://www.economist.com/node/17627815 It discuses some of the roles of ICANN: the Internet Corporation for Assigned Names and Numbers. There are a few typos in the text, but other than that it’s somewhat informative. What does ICANN oversee? (1 point) Top level domain registries. 2. What do governments want a say over, and why? Over what internet addresses can be used.
|
