School 2.0 - Bandwidth Planner

Glossary

bandwidth	The transmission capacity of an electronic pathway such as a communications line, computer bus or computer channel. In a digital line, it is measured in bits per second or bytes per second. In an analog channel or in a digital channel that is wrapped in a carrier frequency, bandwidth is the difference between the highest and lowest frequencies and is measured in Hertz (kHz, MHz, GHz). [Answers.com: Science (2005). From Computer Desktop Encyclopedia. The Computer Language Co. Inc. Available online at: http://www.answers.com/topic/bandwidth?cat=biz-fin. ]

utilization	A percentage of the bandwidth being used for transmissions. It is generally found by sampling usage during different time periods.

peak utilization	The maximum volume on a connection, typically also found by sampling.

dial-up	A connection to the Internet through a modem that runs over any telephone line with no special setup required (unlike a DSL line). A dialup connection ties up the telephone line over which it is running.

ISDN	Integrated Services Digital Network (ISDN) connections can carry data, voice, video, and fax over one line. The transmission is digital, which makes it clearer. ISDN is typically used for videoconferencing. [http://communication.howstuffworks.com/how-video-conferencing-security-works2.htm]

DSL	Digital Subscriber Line (DSL) uses ordinary telephone wires to achieve a high-speed connection. It requires a special modem and a setup by the phone company, but the line can be shared (unlike a dialup modem). [http://electronics.howstuffworks.com/dsl.htm]

T-1 Line	A special type of telephone line for digital communication and transmission. Generally, a T-1 line will move a megabyte of data in under 10 seconds. That still is not fast enough for full-screen, full-motion video, for which at least 10,000,000 bits per second is required. T-1 is the fastest speed commonly used to connect networks to the Internet. [Computer Terms Explained (no date). Metro Computers LLC. Available online at: http://metrocomputers.com/Computer%20Terms.htm]

cable	A connection that runs on the cable that provides a TV signal. Both data transfers and TV signals can operate at once. Basically, the Internet connection uses a channel that a TV station would normally occupy. [ http://computer.howstuffworks.com/cable-modem.htm]

wireless network	Refers to any network that transmits radio signals over the air, such as a wireless local area network, cell phone network, or satellite network. It does not require line of sight between sender and receiver. Wireless base stations (access points) are wired to an Ethernet network and transmit a radio frequency over an area of several hundred feet through walls and other non-metal barriers. Roaming users can be handed off from one access point to another as in a cellular phone system. [TechEncyclopedia (no date). The Tech Web Network. Available online at: http://www.techweb.com/encyclopedia/defineterm.jhtml?term=wirelessLAN]

fractional T-3	Like a T-1 but carries more data. Comes in fractional units of T-1s up to 28.

OC-1	A fiber optic-based connection. Fiber optics uses glass inside the cable for less expense (e.g., than copper), more capacity, better signal quality, lower power consumption, lower weight, and greater flexibility. [http://www.webopedia.com/TERM/O/OC.html See also: http://www.webopedia.com/TERM/F/fiber_optics.htm]

OC-3	Like OC-1 but runs at three times the rate. [http://www.webopedia.com/TERM/O/OC.html]

e-mail and web browsing	Refers to common Internet applications such as downloading email to read or browsing websites, even those websites that are media-rich.

VoIP (Voice over IP)	An application that allows telephone calls to be placed over the Internet.

online learning	Interactive environments in which students connect to a web server over the Internet that hosts content (text and animations) for learning. Can include online testing, course management, and bulletin boards.

audio streaming	Playing audio content from a web server over the Internet in real time. (Contrasts with an audio download that is played back at a later time.)

TV-quality video streaming to a desktop	Playing video content from a web server over the Internet in real time. TV-quality refers to the sharpness of the video picture. (Contrasts with a video download that is played back at a later time.)

interactive video at a desktop	Generally refers to video teleconferencing. Allows multiple people to feed video streams in real-time to each others desktops.

online assessment for each student	Online test taking management systems from assessment companies, states, or school districts.

virtual field trips	Multimedia content (text, animations, video, and audio) accompanied by interactive sessions with scientists or expedition leaders.

student-created content	Internet web pages that are produced by students and that are served from (for example) a school website. An instance of an application that can impact upload speeds. Most internet service providers (ISPs) figure that users will use less bandwidth for upload and more for download.

school portal	A website that is a gateway to many school-related services (announcements, events, directories, etc.). An instance of an application that can impact upload speeds. Most internet service providers (ISPs) figure that users will use less bandwidth for upload and more for download.

cache	A temporary storage area where frequently accessed data can be stored for rapid access. Once the data is stored in the cache, users can access the cached copy rather than refetching or recomputing the original data, so that the average access time is shorter. Cache, therefore, helps expedite data access that the CPU would otherwise need to fetch from main memory. [www.wikepedia.com]

class A IP address	An IP address in which the highest order bit is set to 0, the next 7 bits are used for the network part, and the remaining 24 bits are used for the local address. In dotted-decimal notation (a series of four decimal numbers separated by periods), the first byte represents the network number, and the other 3 bytes are available for the host number. Class A addresses are assigned the numbers 1 through 126 as the first byte. [http://www.cisco.com/univercd/cc/td/doc/product/rtrmgmt/cwhubs/starvwug/83428.htm]

class B IP address	An IP address in which the 2 highest-order bits are set to 10, the next 14 bits are used for the network part, and the remaining 16 bits are used for the local address. In dotted-decimal notation (a series of four decimal numbers separated by periods), the first 2 bytes represent the network number, and the remaining 2 bytes are available for the host number. Class B addresses are assigned the numbers 128.1 through 191.255 as the first 2 bytes. [http://www.cisco.com/univercd/cc/td/doc/product/rtrmgmt/cwhubs/starvwug/83428.htm]

IP address	A 32-bit binary number. For convenience, it is often written as a series of four decimal numbers separated by periods (dotted-decimal notation). Each decimal number represents 8 bits and is referred to as a byte or octet. IP addresses are made up of two parts. The first part identifies the network, and the second part identifies the local or host address. There are five classes of address, labeled A through E, according to how the address divides the network and local parts. An IP address obtained from the Internet Network Information Center (NIC) and used for communication on the Internet is called an Internet address. [http://www.cisco.com/univercd/cc/td/doc/product/rtrmgmt/cwhubs/starvwug/83428.htm]

NAT (NAT'ing)	Network Address Translation (NAT) allows computers on a private network to access the Internet without requiring their own global (public) Internet address. NAT modifies outgoing network packets so that the return address is a valid Internet host. Return (incoming) packets have their destination address changed back, and are relayed to the client host, thereby protecting the private addresses from public view. [http://www.ml-ip.com/html/support/glossary.html]