Download Backbone: the main connecting cable that runs from one end of the

Fangqin Li
CS600
Homework 4
Definition
Cloud- the portion of the internet lying outside of its gateway is sometimes called the
cloud.
Domain- a domain consists of a network or a relatively small internet operated by a
single organization such as a university, company, or government institution. Each
domain is an autonomous system that can be configured as the local authority
desires, perhaps even as a global collection of WANs.
Dotted Decimal- IP address are traditionally written in dotted decimal notation in
which the bytes of the address are separated by periods and each byte is expressed
as an integer represented in traditional base ten notation.
Ethemet- it is a popular version of a bus network.
firewall- is a software in that it forms a protective barrier that shields the region on
one side from the dangers on the other.
FTP- is a client/server protocol for transferring files across the Internet.
HTML- The distinction is that a hypertext document also contains special symbols,
called tags, that decribes how the document should appear on a computer screen
and which items within the document are linked to other documents. This system of
tags is known as Hypertext Markup Language (HTML).
internet- the two networks can be connected in a manner that builds a network of
networks, which is known as an internet.
IP- The Internet Protocol (IP) is a data-oriented protocol used for communicating
data across a packet-switched internetwork. IP is a network layer protocol in the
Internet protocol suite and is encapsulated in a data link layer protocol (e.g.,
Ethernet). As a lower layer protocol, IP provides the service of communicable unique
global addressing amongst computers.
IP address- An IP address (or Internet Protocol address) is a unique address that
certain electronic devices use in order to identify and communicate with each other
on a computer network utilizing the Internet Protocol standard (IP).
1
Packet- a formatted block of data carried by a packet mode computer network.
protocol- is a convention or standard that controls or enables the connection,
communication, and data transfer between two computing endpoints. In its simplest
form, a protocol can be defined as the rules governing the syntax, semantics, and
synchronization of communication. Protocols may be implemented by hardware,
software, or a combination of the two. At the lowest level, a protocol defines the
behavior of a hardware connection.
router- the connection between two networks to form an internet is handled by a
machine known as a router, which is a computer belonging to both networks that
forwards messages in one network into the other network.
search engine- is a software package designed to help Web users identify
documents pertaining to various subjects.
tier-1 ISP- An Internet service provider (abbr. ISP, also called Internet access
provider or IAP) is a company or business that provides access to the Internet and
related services.
UDP- is one of the core protocols of the Internet protocol suite. Using UDP,
programs on networked computers can send short messages sometimes known as
datagrams (using Datagram Sockets) to one another. UDP is sometimes called the
Universal Datagram Protocol.
XML- is a standardized style (similar to that of our music example) for designing
notational systems for representing data as text files.
Questions
1. protocolis a convention or standard that controls or enables the connection,
communication, and data transfer between two computing endpoints. In its simplest
form, a protocol can be defined as the rules governing the syntax, semantics, and
synchronization of communication. Protocols may be implemented by hardware,
software, or a combination of the two. At the lowest level, a protocol defines the
behavior of a hardware connection.Three protocols are: TCP, IP, and UDP. TCP
provides reliable, in-order delivery of a stream of bytes, making it suitable for
applications like file transfer and e-mail. It is so important in the Internet protocol
2
suite that sometimes the entire suite is referred to as "the TCP/IP protocol suite."
TCP is the transport protocol that manages the individual conversations between
web servers and web clients. TCP divides the HTTP messages into smaller pieces,
called segments, to be sent to the destination client. It is also responsible for
controlling the size and rate at which messages are exchanged between the server
and the client. IP provides the service of communicable unique global addressing
amongst computers. UDP does not establish a connection to send a message. It
merely sends the message to the address it was given and forgets about it. UDP
does not offer such retransmission services. A transport layer based on UDP is more
streamlined than a layer based on TCP.
2.It defines the basic roles played by the processes as either a client, which makes
requests of other processes, or a server, which satisfies the requests made by
clients.
3.It involves processes that provide service to and receive service from each other.
4.A computer network is often classified as being a LAN, a MAN, or a WAN. Another
means of classifying networks is based on whether the network’s internal operation
is based on designs that are in the public domain or on innovations owned and
controlled by a particular entity.
5.A network of the public domain is called an open network; a network of the
innovations owned and controlled by a particular entity such as an individual or a
corporation is called a closed or sometimes a proprietary network.
6.Because a machine may be unable to detect that its transmissions are colliding
with those of another and the signals from the different machines are blocked form
each other by objects or distance even though they can all communicate with the
central AP.
7.To transmit a message, a machine waits until the bus is silent, and at this time it
begins transmitting while continuing to monitor the bus. If another machine also
begins transmitting, both machines detect the clash and pause for a brief,
independently random period of time before trying to transmit again.
8.It is that wireless networks adopt the policy of trying to avoid collisions rather than
trying to detect them. To solve this problem, some WiFi networks require that each
3
machine send a short “request ” message to the AP and wait until the AP
acknowledges that request before transmitting an entire message.
9.All hub does is relay any signal it receives back out to all the machines connected
to it. A repeater is little more than a device that simply passes signals back and forth
between the two original buses without considering the meaning of the signals.
10.Routers provide links between networks while allowing each network to maintain
its unique internal characteristics.
13. The source of this distinction is that when printing a text document with early
teletype devices, a new line of text required both a line feed (a vertical
movement) and a carriage return ( a horizontal movement) , each of which is
encoded individually in ASCII. (A line feed is indicated by the pattern 00001010,
whereas a carriage return is indicated by 00001101).
15. a.
0000000000000000;
b.
000110010001001000000001;
c.
00000101000011000000110100001010.
17. The process of using the DNS to perform a translation is called a DNS lookup.
19. Kermit: a symbol string identifying the individual; animals.com: the mnemonic
string.
21. Providing mail service to users within its realm.
23. a. The conversion is performed with the aid of numerous servers, called name
servers which are essentially directories that provide address translation services
to clients. b. It is essentially an independent internet, sometimes called an
intranet, operated by a single authority that is in the business of supplying
Internet access to individual users. c. It handles the connection between
networks to form an internet and is special purpose computers used for
forwarding messages. d. the devices that individual users connect to the access
ISPs are known as end systems.
25. The networks must be connected in a manner that builds a network of networks
which is an internet. The web that has evolved on the Internet spans the entire
globe and is known as the WWW.
27. <head>: it contains preliminary information about the document; <body>: it
contains the meat of the document which in the case of a web page is the
4
material to be presented on the computer screen when the page is displayed;
<h1>: it is a level-one heading; <p>: it is a paragraph of text; <html>: it means the
start of the HTML; <title>: the HTML’s title.
29. My Pet Dog
31. <ingredient>bold</ingredient>;
<ingredient>italic</ingredient>;
<ingredient>underlined</ingredient>.
33. The Open Systems Interconnection Basic Reference Model (OSI Reference
Model or OSI Model for short) is a layered, abstract description for
communications and computer network protocol design. It was developed as
part of the Open Systems Interconnection (OSI) initiative and is sometimes
known as the OSI seven layer model. From top to bottom, the OSI Model
consists of the Application, Presentation, Session, Transport, Network, Data
Link, and Physical layers.
35. a. http: Protocol required to access the document. In this case it is hypertext
transfer protocol; www.formtools.org: Mnemonic name of host holding the
document; windmills.html: document name. b. http: Protocol required to access
the document. In this case it is hypertext transfer protocol; castles.org:
Mnemonic name of host holding the document. c. www.coolstuff.com:
Mnemonic name of host holding the document.
5