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Bandwidth (computing) 1

Bandwidth (computing)

In computer networking and computer science, the words bandwidth,[1]

network bandwidth,[2]

data bandwidth,[3]

or digital bandwidth[4][5]

are colloquial and metaphoric terms widely used in textbooks[6]

as well as scientific

papers, patents and standards[7]

to refer to various bit-rate measures, representing the available or consumed data

communication resources expressed in bits/second or multiples of it (kilobits/s, megabits/s etc.).

Note that in textbooks on signal processing, wireless communications, modem data transmission, digital

communications, electronics, etc., the word 'bandwidth' is used to refer to analog signal bandwidth measured in hertz

the original meaning of the term. Some computer networking authors prefer less ambiguous terms such as bit

rate, channel capacity and throughputrather than the colloquial use of the word 'bandwidth' for bit/s, to avoid this

confusion.

Network bandwidth capacity

Bandwidth sometimes defines the net bit rate (aka. peak bit rate, information rate or physical layer useful bit rate),

channel capacity, or the maximum throughput of a logical or physical communication path in a digital

communication system. For example, bandwidth tests measure the maximum throughput of a computer network. The

reason for this usage is that according to Hartley's law, the maximum data rate of a physical communication link is

proportional to its bandwidth in hertz, which is sometimes called frequency bandwidth, spectral bandwidth, RF

bandwidth, signal bandwidth or analog bandwidth.

Network bandwidth consumption

Bandwidth in bit/s may also refer to consumed bandwidth, corresponding to achieved throughput or goodput, i.e., the

average rate of successful data transfer through a communication path. This sense applies to expressions such as

bandwidth shaping, bandwidth management, bandwidth throttling, bandwidth cap, bandwidth allocation (forexample bandwidth allocation protocol and dynamic bandwidth allocation), etc. A bit stream's bandwidth is

proportional to the average consumed signal bandwidth in Hertz (the average spectral bandwidth of the analog signal

representing the bit stream) during a studied time interval.

Channel bandwidth may be confused with data throughput. A channel withx bps may not necessarily transmit data at

x rate, since protocols, encryption, and other factors can add appreciable overhead. For instance, a lot of internet

traffic uses the transmission control protocol (TCP) which requires a three-way handshake for each transaction,

which, though in many modern implementations is efficient, does add significant overhead compared to simpler

protocols. In general, for any effective digital communication, a framing protocol is needed; overhead and effective

throughput depends on implementation. Actual throughput is less than or equal to the actual channel capacity plus

implementation overhead.

Asymptotic bandwidth

The asymptotic bandwidth for a network is the measure of useful throughput, when the packet size approaches

infinity.[8]

Asymptotic bandwidths are usually estimated by sending a number of very large messages through the network,

measuring the end-to-end throughput. As other bandwidths, the asymptotic bandwidth is measured in multiples of

bits/second, e.g. megabits per second, etc.

http://en.wikipedia.org/w/index.php?title=Network_packethttp://en.wikipedia.org/w/index.php?title=Throughputhttp://en.wikipedia.org/w/index.php?title=Dynamic_bandwidth_allocationhttp://en.wikipedia.org/w/index.php?title=Bandwidth_allocation_protocolhttp://en.wikipedia.org/w/index.php?title=Bandwidth_allocationhttp://en.wikipedia.org/w/index.php?title=Bandwidth_caphttp://en.wikipedia.org/w/index.php?title=Bandwidth_throttlinghttp://en.wikipedia.org/w/index.php?title=Bandwidth_managementhttp://en.wikipedia.org/w/index.php?title=Bandwidth_shapinghttp://en.wikipedia.org/w/index.php?title=Goodputhttp://en.wikipedia.org/w/index.php?title=Throughputhttp://en.wikipedia.org/w/index.php?title=Radio_frequencyhttp://en.wikipedia.org/w/index.php?title=Bandwidth_%28signal_processing%29http://en.wikipedia.org/w/index.php?title=Hartley%27s_lawhttp://en.wikipedia.org/w/index.php?title=Bandwidth_testhttp://en.wikipedia.org/w/index.php?title=Maximum_throughputhttp://en.wikipedia.org/w/index.php?title=Channel_capacityhttp://en.wikipedia.org/w/index.php?title=Net_bit_ratehttp://en.wikipedia.org/w/index.php?title=Throughputhttp://en.wikipedia.org/w/index.php?title=Channel_capacityhttp://en.wikipedia.org/w/index.php?title=Bit_ratehttp://en.wikipedia.org/w/index.php?title=Bit_ratehttp://en.wikipedia.org/w/index.php?title=Hertzhttp://en.wikipedia.org/w/index.php?title=Signal_bandwidthhttp://en.wikipedia.org/w/index.php?title=Electronicshttp://en.wikipedia.org/w/index.php?title=Digital_communicationshttp://en.wikipedia.org/w/index.php?title=Digital_communicationshttp://en.wikipedia.org/w/index.php?title=Data_transmissionhttp://en.wikipedia.org/w/index.php?title=Modemhttp://en.wikipedia.org/w/index.php?title=Wireless_communicationshttp://en.wikipedia.org/w/index.php?title=Signal_processinghttp://en.wikipedia.org/w/index.php?title=Bit-ratehttp://en.wikipedia.org/w/index.php?title=Computer_sciencehttp://en.wikipedia.org/w/index.php?title=Computer_networking

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Bandwidth (computing) 2

Multimedia bandwidth

Digital bandwidth may also refer to: multimedia bit rate or average bitrate after multimedia data compression (source

coding), defined as the total amount of data divided by the playback time.

Bandwidth in web hosting

In website hosting, the term "bandwidth" is often incorrectly used to describe the amount of data transferred to or

from the website or server within a prescribed period of time, for example bandwidth consumption accumulated over

a month measured in gigabytes per month. The more accurate phrase used for this meaning of a maximum amount of

data transfer each month or given period is monthly data transfer.

Internet connection bandwidths

This table shows the maximum bandwidth (the physical layer net bitrate) of common Internet access technologies.

For more detailed lists see

list of device bandwidths

bit rate progress trends

list of multimedia bit rates.

56 kbit/s Modem / Dialup

1.5 Mbit/s ADSL Lite

1.544 Mbit/s T1/DS1

10 Mbit/s Ethernet

11 Mbit/s Wireless 802.11b

44.736 Mbit/s T3/DS3

54 Mbit/s Wireless 802.11g

100 Mbit/s Fast Ethernet

155 Mbit/s OC3

600 Mbit/s Wireless 802.11n

622 Mbit/s OC12

1 Gbit/s Gigabit Ethernet

2.5 Gbit/s OC48

9.6 Gbit/s OC192

10 Gbit/s 10 Gigabit Ethernet

100 Gbit/s 100 Gigabit Ethernet

http://en.wikipedia.org/w/index.php?title=100_Gigabit_Ethernethttp://en.wikipedia.org/w/index.php?title=10_Gigabit_Ethernethttp://en.wikipedia.org/w/index.php?title=OC192http://en.wikipedia.org/w/index.php?title=OC48http://en.wikipedia.org/w/index.php?title=Gigabit_Ethernethttp://en.wikipedia.org/w/index.php?title=OC12http://en.wikipedia.org/w/index.php?title=802.11nhttp://en.wikipedia.org/w/index.php?title=OC3http://en.wikipedia.org/w/index.php?title=Fast_Ethernethttp://en.wikipedia.org/w/index.php?title=802.11ghttp://en.wikipedia.org/w/index.php?title=Digital_Signal_3http://en.wikipedia.org/w/index.php?title=802.11bhttp://en.wikipedia.org/w/index.php?title=Ethernethttp://en.wikipedia.org/w/index.php?title=Digital_Signal_1http://en.wikipedia.org/w/index.php?title=ADSL_Litehttp://en.wikipedia.org/w/index.php?title=Bit_rate%23Multimediahttp://en.wikipedia.org/w/index.php?title=Bit_rate%23Progress_trendshttp://en.wikipedia.org/w/index.php?title=List_of_device_bandwidthshttp://en.wikipedia.org/w/index.php?title=Net_bitratehttp://en.wikipedia.org/w/index.php?title=Web_hosting_servicehttp://en.wikipedia.org/w/index.php?title=Source_codinghttp://en.wikipedia.org/w/index.php?title=Source_codinghttp://en.wikipedia.org/w/index.php?title=Data_compressionhttp://en.wikipedia.org/w/index.php?title=Average_bitratehttp://en.wikipedia.org/w/index.php?title=Bit_rate%23Multimedia

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Bandwidth (computing) 3

References

[1] Andrew S. Tanenbaum Computer networks (http://books. google. com/books?id=Pd-z64SJRBAC& printsec=frontcover&

dq=intitle:computer+ intitle:networks+inauthor:tanenbaum& hl=en& ei=uPScTOulBYG2sAOris3XAQ&sa=X&oi=book_result&

ct=result&resnum=1& ved=0CC8Q6AEwAA#v=snippet& q=bandwidth kbps&f=false), Prentice Hall PTR, 2003

[2] Douglas Comer, Computer Networks and Internets (http://books. google. com/books?id=tm-evHmOs3oC& pg=PA99& dq="network+

bandwidth"+ "computer+ networks"&hl=en& ei=mvqcTOHIMIb2tgPbnpXWAQ& sa=X&oi=book_result& ct=result&resnum=2&

ved=0CDIQ6AEwAQ#v=onepage& q&f=false), page 99 ff, Prentice Hall 2008.[3] Fred Halsall, Introduction to data communications and computer networks (http://books. google. com/

books?ei=dvycTJ2BDoqosAOhu_DVAQ& ct=result&hl=en&id=HrXbAAAAMAAJ&dq="data+bandwidth"+ +"computer+ networks"&

q="data+ bandwidth"+), page 108, Addison-Wesley, 1985.

[4] Cisco Networking Academy Program: CCNA 1 and 2 companion guide, Volym 12 (http://books. google. com/

books?ei=rfmcTPKEN5L6swOekeXVAQ&ct=result&hl=en& id=7gqsZmr5HJcC& dq="digital+ bandwidth"+ "computer+ networks"&

q="digital+ bandwidth"), Cisco Academy 2003

[5] Behrouz A. Forouzan,Data communications and networking, McGraw-Hill, 2007

[6] Search in Google Books for textbooks on "Network bandwidth" (https://www.google. com/search?q="network+bandwidth"&

btnG=Search+ Books& tbm=bks& tbo=1) (96.900 hits in April 2012)

[7] Search in google scholar for academic research papers on "Network bandwidth" (http://scholar.google. se/scholar?hl=en& q="network+

bandwidth"+ &btnG=Search& as_sdt=0,5&as_ylo=& as_vis=0) (84.500 hits in April 2012)

[8] Modeling Message Passing Overheadby C.Y Chou et al. in Advances in Grid and Pervasive Computing: First International Conference, GPC

2006 edited by Yeh-Ching Chung and Jos E. Moreira ISBN 3540338098 pages 299-307

http://scholar.google.se/scholar?hl=en&q=%22network+bandwidth%22+&btnG=Search&as_sdt=0%2C5&as_ylo=&as_vis=0http://scholar.google.se/scholar?hl=en&q=%22network+bandwidth%22+&btnG=Search&as_sdt=0%2C5&as_ylo=&as_vis=0https://www.google.com/search?q=%22network+bandwidth%22&btnG=Search+Books&tbm=bks&tbo=1https://www.google.com/search?q=%22network+bandwidth%22&btnG=Search+Books&tbm=bks&tbo=1http://en.wikipedia.org/w/index.php?title=Behrouz_A._Forouzanhttp://books.google.com/books?ei=rfmcTPKEN5L6swOekeXVAQ&ct=result&hl=en&id=7gqsZmr5HJcC&dq=%22digital+bandwidth%22+%22computer+networks%22&q=%22digital+bandwidth%22http://books.google.com/books?ei=rfmcTPKEN5L6swOekeXVAQ&ct=result&hl=en&id=7gqsZmr5HJcC&dq=%22digital+bandwidth%22+%22computer+networks%22&q=%22digital+bandwidth%22http://books.google.com/books?ei=rfmcTPKEN5L6swOekeXVAQ&ct=result&hl=en&id=7gqsZmr5HJcC&dq=%22digital+bandwidth%22+%22computer+networks%22&q=%22digital+bandwidth%22http://books.google.com/books?ei=dvycTJ2BDoqosAOhu_DVAQ&ct=result&hl=en&id=HrXbAAAAMAAJ&dq=%22data+bandwidth%22++%22computer+networks%22&q=%22data+bandwidth%22+http://books.google.com/books?ei=dvycTJ2BDoqosAOhu_DVAQ&ct=result&hl=en&id=HrXbAAAAMAAJ&dq=%22data+bandwidth%22++%22computer+networks%22&q=%22data+bandwidth%22+http://books.google.com/books?ei=dvycTJ2BDoqosAOhu_DVAQ&ct=result&hl=en&id=HrXbAAAAMAAJ&dq=%22data+bandwidth%22++%22computer+networks%22&q=%22data+bandwidth%22+http://en.wikipedia.org/w/index.php?title=Fred_Halsallhttp://books.google.com/books?id=tm-evHmOs3oC&pg=PA99&dq=%22network+bandwidth%22+%22computer+networks%22&hl=en&ei=mvqcTOHIMIb2tgPbnpXWAQ&sa=X&oi=book_result&ct=result&resnum=2&ved=0CDIQ6AEwAQ#v=onepage&q&f=falsehttp://books.google.com/books?id=tm-evHmOs3oC&pg=PA99&dq=%22network+bandwidth%22+%22computer+networks%22&hl=en&ei=mvqcTOHIMIb2tgPbnpXWAQ&sa=X&oi=book_result&ct=result&resnum=2&ved=0CDIQ6AEwAQ#v=onepage&q&f=falsehttp://books.google.com/books?id=tm-evHmOs3oC&pg=PA99&dq=%22network+bandwidth%22+%22computer+networks%22&hl=en&ei=mvqcTOHIMIb2tgPbnpXWAQ&sa=X&oi=book_result&ct=result&resnum=2&ved=0CDIQ6AEwAQ#v=onepage&q&f=falsehttp://en.wikipedia.org/w/index.php?title=Douglas_Comerhttp://books.google.com/books?id=Pd-z64SJRBAC&printsec=frontcover&dq=intitle:computer+intitle:networks+inauthor:tanenbaum&hl=en&ei=uPScTOulBYG2sAOris3XAQ&sa=X&oi=book_result&ct=result&resnum=1&ved=0CC8Q6AEwAA#v=snippet&q=bandwidth%20kbps&f=falsehttp://books.google.com/books?id=Pd-z64SJRBAC&printsec=frontcover&dq=intitle:computer+intitle:networks+inauthor:tanenbaum&hl=en&ei=uPScTOulBYG2sAOris3XAQ&sa=X&oi=book_result&ct=result&resnum=1&ved=0CC8Q6AEwAA#v=snippet&q=bandwidth%20kbps&f=falsehttp://books.google.com/books?id=Pd-z64SJRBAC&printsec=frontcover&dq=intitle:computer+intitle:networks+inauthor:tanenbaum&hl=en&ei=uPScTOulBYG2sAOris3XAQ&sa=X&oi=book_result&ct=result&resnum=1&ved=0CC8Q6AEwAA#v=snippet&q=bandwidth%20kbps&f=falsehttp://en.wikipedia.org/w/index.php?title=Andrew_S._Tanenbaum

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Article Sources and Contributors 4

Article Sources and ContributorsBandwidth (computing) Source: http://en.wikipedia.org/w/index.php?oldid=493767998 Contributors: 16@r, Airplaneman, Alro, Anagogist, Anna Lincoln, Arcticaribou, Baseball Bugs,

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