Types of Websites, Development Sites, Simple sites that compaines use to evaluate different Web designs with little initial investment., Intranets, Corporate networks that house internal memos, corp- orate policy handbooks, budgets, newsletters, etc., Extranets, Intranets that allow certain authorized parties outside the company to access certain parts of the info stored in system., Transaction-processing, B2B or B2C sites that must be available 24/7., Content-delivery sites, Sites that deliver content such as news, histories, summaries, and other digital info.
Web Clients and Web- servers, When people use Internet connections to become part of the Web, their computers become Web client computers on a worldwide client/server architecture These architectures are used in LANs, WANs, and the Web.
Dynamic Content, non static info constructed in response to a Web client's request.
Web Client/Server Communication, In order to display a site the Web Client starts off by opening his internet browser. In order for a site to be displayed, the server containing site files must be contacted through the internet. It is a matter of receiving files from the server through the internet connection that the Web client is connected to.
Two-Tier Client/Server Architecture, Client/server architecture in which only a client and server are involved in the requests and responses that flow between them over the internet.
Three-Tier and N-Tier architecture, extends the two-tier architecture to allow additional processing to occur before the Web server responds to the Web client's request. N-tier is a higher order client server architectures that have more than three tiers.
Web page whose content is shaped by a program in response to user requests.
Unchanging page retrieved from disk.
programs running on the Web server create the Web pages before sending them back to the requesting Web clients as parts of response messages.
any computer used to provide files or make programs available to other computers connected to it through a network (ex: LAN/VAN)
Softeare the server computer uses to make these files and programs available to the other computers.
Server computer is connected to the Internet and is running Web server software.
Server computer on which database management software runs.
HTTP message that a Web client sends to request a file or files from a Web server.
Email message that is incorrectly rejected by an email filter as being spam when is is actually valid email.
FTP connection to a computer on which the user has an account.
examines each page on the site and reports on any URLs that seem broken or incorrect.
A file on the web site that is not linked to any page.
feature that maintains more than one server on on machine.
Tasks include running programs and allocating computer resources such as memory and disk space to programs. Operating system software also provides input and output services to devices connected to the computer.
Apache HTTP server
Sun Java system
Quick and effective medium of delivering messages. Documents, pictures, movies, worksheets, etc can be sent along with a message. Email is a convienent way to send information fast.
The amount of time business people spend answering their email today. Another drawback/irritation is that a computer virus that can be contracted through email.
Bulk mail or Junk mail that contains nearly identical messages send to multiple email address. Spam has the ability to contain viruses and other harmful effects to internet users and servers alike.
Individual user antispam tactics, 1. Reduce the likelihood that a spammer can automatically generate their email addresses. 2. Control the exposure of an email address. 3. Some people use multiple email addresses to thwart spam
Basic Content Filtering, Black list filter, looks for "From" addresses in incoming messages that are known to be spammers. Software can delete the message or put it into a separate mailbox for review., White list filter, examines "From" addresses and compares them to a list of known good sender addresses. Usually applied at the individual user level.
Challenge-Response Content Filtering, compares all incoming messages to a white list. If the message is from a sender who is not on the white list, an automated email respnse is sent to the sender. This message (challenge) asks the sender to reply to the email. Drawbacks include: abuse.
Legal Solutions, Many laws have been put forward and will continue to be put forward in order to help control spam. In Jan 04, the U.S. CAN-SPAM law went into effect. It regulates all email messages send for the primary purpose of advertising for promoting commercial products/services including display of content.
A finger is a program that runs on UNIX operating systems and allows a user to obtain some info about other networks. A Ping tests the connectivity between 2 copmuters connected to the internet.
Tracert sends data packets to every computer on the path between one computer and another computer and clocks the packets' round-trip times. This provides the time a message takes to be delivered.
Telmet is a program that allows users to log on to a computer that is connected to the internet. This login capability can be useful for running older software that does not have a Web interface. FTP is the part of the TCP/IP rules that defines the formats used to transfer files between TCP/IP-connected computers.
An indexing program can provide full-text indexing that generates an index for all documents stored on the server. Search engines search either a specific site or the entire Web for requested documents.