Editing Internet access (section)

==Availability==
[[File:Internet Connectivity Access layer.svg|thumb|Internet Connectivity Access layer]]
In addition to access from home, school, and the workplace Internet access may be available from [[public place]]s such as [[libraries]] and [[Internet café]]s, where computers with Internet connections are available. Some libraries provide stations for physically connecting users' [[laptop]]s to LANs.

Wireless Internet access points are available in public places such as airport halls, in some cases just for brief use while standing. Some access points may also provide coin-operated computers. Various terms are used, such as "public [[Internet kiosk]]", "public access terminal", and "Web [[payphone]]". Many hotels also have public terminals, usually fee based.

Coffee shops, shopping malls, and other venues increasingly offer wireless access to computer networks, referred to as [[Hotspot (Wi-Fi)|hotspots]], for users who bring their own wireless-enabled devices such as a [[laptop]] or [[personal digital assistant|PDA]]. These services may be free to all, free to customers only, or fee-based. A Wi-Fi hotspot need not be limited to a confined location since multiple ones combined can cover a whole campus or park, or even an entire city can be enabled.

Additionally, mobile broadband access allows [[smartphone]]s and other digital devices to connect to the Internet from any location from which a [[mobile phone]] call can be made, subject to the capabilities of that mobile network.

===Speed===
{{Main|Data signaling rate|Bit rate|Bandwidth (computing)|List of interface bit rates|List of countries by Internet connection speeds}}
{{see also|Data-rate units}}
The bit rates for dial-up [[modems]] range from as little as 110 bit/s in the late 1950s, to a maximum of from 33 to 64&nbsp;kbit/s ([[ITU-T V.90|V.90]] and [[ITU-T V.92|V.92]]) in the late 1990s. Dial-up connections generally require the dedicated use of a telephone line. Data compression can boost the effective bit rate for a dial-up modem connection from 220 ([[ITU-T V.42bis|V.42bis]]) to 320 ([[ITU-T V.44|V.44]])&nbsp;kbit/s.<ref>{{cite web|url=http://fndcg0.fnal.gov/Net/modm8-94.txt |title=What You Need to Know about Modems |access-date=2008-03-02 |last=Willdig |first=Karl |author2=Patrik Chen |date=August 1994 |url-status=dead |archive-url=https://web.archive.org/web/20070104124418/http://fndcg0.fnal.gov/Net/modm8-94.txt |archive-date=2007-01-04 }}</ref> However, the effectiveness of data compression is quite variable, depending on the type of data being sent, the condition of the telephone line, and a number of other factors. In reality, the overall data rate rarely exceeds 150&nbsp;kbit/s.<ref>{{cite web |url=https://www.pricenfees.com/digit-life-archives/modem-compression-v-44-v-42bis |title=Modem compression: V.44 against V.42bis |access-date=2008-03-02 |last=Mitronov |first=Pavel |date=2001-06-29 |publisher=Pricenfees.com |url-status=dead |archive-url=https://web.archive.org/web/20170202062749/https://www.pricenfees.com/digit-life-archives/modem-compression-v-44-v-42bis |archive-date=2017-02-02 }}</ref>

Broadband technologies supply considerably higher bit rates than dial-up, generally without disrupting regular telephone use. Various minimum data rates and maximum latencies have been used in definitions of broadband, ranging from 64&nbsp;kbit/s up to 4.0&nbsp;Mbit/s.<ref name="Birth">{{cite web |url=http://www.itu.int/osg/spu/publications/birthofbroadband/faq.html |title=Birth of Broadband |publisher=ITU |date=September 2003 |access-date=July 12, 2011 |url-status=live |archive-url=https://web.archive.org/web/20110701173257/http://www.itu.int/osg/spu/publications/birthofbroadband/faq.html |archive-date=July 1, 2011 }}</ref> In 1988 the [[ITU-T|CCITT]] standards body defined "broadband service" as requiring transmission channels capable of supporting [[bit rate]]s greater than the [[Primary Rate Interface|primary rate]] which ranged from about 1.5 to 2&nbsp;Mbit/s.<ref>{{cite web |url= http://www.itu.int/rec/dologin_pub.asp?lang=e&id=T-REC-I.113-199706-I!!PDF-E |title= Recommendation I.113, Vocabulary of Terms for Broadband aspects of ISDN |publisher= ITU-T |date= June 1997 |orig-year= originally 1988 |access-date= 19 July 2011 |url-status= live |archive-url= https://web.archive.org/web/20121106141554/http://www.itu.int/rec/dologin_pub.asp?lang=e&id=T-REC-I.113-199706-I!!PDF-E |archive-date= 6 November 2012 }}</ref> A 2006 [[Organisation for Economic Co-operation and Development]] (OECD) report defined broadband as having download [[data transfer rates]] equal to or faster than 256&nbsp;kbit/s.<ref name="OECD">{{cite web |url=http://www.fcc.gov/cgb/broadband.html |title=2006 OECD Broadband Statistics to December 2006 |publisher=OECD |access-date=June 6, 2009 |url-status=dead |archive-url=https://web.archive.org/web/20090507202240/http://www.fcc.gov/cgb/broadband.html |archive-date=2009-05-07 }}</ref> And in 2015 the U.S. [[Federal Communications Commission]] (FCC) defined "Basic Broadband" as data transmission speeds of at least 25&nbsp;Mbit/s downstream (from the Internet to the user's [[computer]]) and 3&nbsp;Mbit/s upstream (from the user's computer to the Internet).<ref>{{cite web |url=https://apps.fcc.gov/edocs_public/attachmatch/DOC-331760A1.pdf |title=FCC Finds U.S. Broadband Deployment Not Keeping Pace |publisher=FCC |access-date=January 29, 2015 |url-status=live |archive-url=https://web.archive.org/web/20150419074040/https://apps.fcc.gov/edocs_public/attachmatch/DOC-331760A1.pdf |archive-date=April 19, 2015 }}</ref> The trend is to raise the threshold of the broadband definition as higher data rate services become available.<ref name="engadget08">{{cite web |first=Nilay |last=Patel |url=https://www.engadget.com/2008/03/19/fcc-redefines-broadband-to-mean-768kbps-fast-to-mean-kinda/ |title=FCC redefines "broadband" to mean 768&nbsp;kbit/s, "fast" to mean "kinda slow" |publisher=Engadget |date=March 19, 2008 |access-date=June 6, 2009 |url-status=live |archive-url=https://web.archive.org/web/20090213175111/http://www.engadget.com/2008/03/19/fcc-redefines-broadband-to-mean-768kbps-fast-to-mean-kinda |archive-date=February 13, 2009 }}</ref>

The higher data rate dial-up modems and many broadband services are "asymmetric"—supporting much higher data rates for download (toward the user) than for upload (toward the Internet).

Data rates, including those given in this article, are usually defined and advertised in terms of the maximum or peak download rate. In practice, these maximum data rates are not always reliably available to the customer.<ref name="100mb"/> Actual end-to-end data rates can be lower due to a number of factors.<ref>{{cite news |author= Tom Phillips |title= 'Misleading' BT broadband ad banned |work= UK Metro |date= August 25, 2010 |url= http://www.metro.co.uk/tech/839014-misleading-bt-broadband-ad-banned |access-date= July 24, 2011 |url-status= live |archive-url= https://web.archive.org/web/20110906220840/http://www.metro.co.uk/tech/839014-misleading-bt-broadband-ad-banned |archive-date= September 6, 2011 }}</ref> In late June 2016, internet connection speeds averaged about 6&nbsp;Mbit/s globally.<ref>{{cite news |author=Ben Munson |title=Akamai: Global average internet speeds have doubled since last Olympics |work=FierceOnlineVideo |date=June 29, 2016 |url=http://www.fierceonlinevideo.com/story/akamai-global-average-internet-speeds-have-doubled-last-olympics/2016-06-29 |access-date=June 30, 2016 |url-status=dead |archive-url=https://web.archive.org/web/20160702073650/http://www.fierceonlinevideo.com/story/akamai-global-average-internet-speeds-have-doubled-last-olympics/2016-06-29 |archive-date=July 2, 2016 }}</ref> Physical link quality can vary with distance and for wireless access with terrain, weather, building construction, antenna placement, and interference from other radio sources. Network bottlenecks may exist at points anywhere on the path from the end-user to the remote server or service being used and not just on the first or last link providing Internet access to the end-user.

===Network congestion===
Users may share access over a common network infrastructure. Since most users do not use their full connection capacity all of the time, this aggregation strategy (known as [[contended service]]) usually works well, and users can burst to their full data rate at least for brief periods. However, [[peer-to-peer]] (P2P) [[file sharing]] and high-quality streaming video can require high data-rates for extended periods, which violates these assumptions and can cause a service to become oversubscribed, resulting in congestion and poor performance. The TCP protocol includes flow-control mechanisms that automatically throttle back on the bandwidth being used during periods of [[network congestion]]. This is fair in the sense that all users who experience congestion receive less bandwidth, but it can be frustrating for customers and a major problem for ISPs. In some cases, the amount of bandwidth actually available may fall below the threshold required to support a particular service such as video conferencing or streaming live video–effectively making the service unavailable.

When traffic is particularly heavy, an ISP can deliberately throttle back the bandwidth available to classes of users or for particular services. This is known as [[traffic shaping]] and careful use can ensure a better [[quality of service]] for time critical services even on extremely busy networks. However, overuse can lead to concerns about fairness and [[network neutrality]] or even charges of [[censorship]], when some types of traffic are severely or completely blocked.

===Outages===
An Internet blackout or outage can be caused by local signaling interruptions. Disruptions of [[submarine communications cable]]s may cause blackouts or slowdowns to large areas, such as in the [[2008 submarine cable disruption]]. Less-developed countries are more vulnerable due to a small number of high-capacity links. Land cables are also vulnerable, as in 2011 when a woman digging for scrap metal severed most connectivity for the nation of Armenia.<ref>{{cite news|agency=The Guardian|url=https://www.theguardian.com/world/2011/apr/06/georgian-woman-cuts-web-access|title=Georgian woman cuts off web access to whole of Armenia|date=6 April 2011|access-date=11 April 2012|url-status=live|archive-url=https://web.archive.org/web/20130825075603/http://www.theguardian.com/world/2011/apr/06/georgian-woman-cuts-web-access|archive-date=25 August 2013}}</ref> Internet blackouts affecting almost entire countries can be achieved by governments as a form of [[Internet censorship]], as in the blockage of the [[Internet in Egypt]], whereby approximately 93%<ref name="renesys1">{{cite web |last=Cowie |first=James |title=Egypt Leaves the Internet |publisher=Renesys |url=http://www.renesys.com/blog/2011/01/egypt-leaves-the-internet.shtml |access-date=28 January 2011 |archive-url=https://web.archive.org/web/20110128080518/http://www.renesys.com/blog/2011/01/egypt-leaves-the-internet.shtml |archive-date=28 January 2011 |url-status=dead |df=dmy-all }}</ref> of networks were without access in 2011 in an attempt to stop mobilization for [[Egyptian Revolution of 2011|anti-government protests]].<ref>{{cite news | url=https://www.bbc.co.uk/news/technology-12306041 | work=BBC News | title=Egypt severs internet connection amid growing unrest | date=28 January 2011 | url-status=live | archive-url=https://web.archive.org/web/20120123164134/http://www.bbc.co.uk/news/technology-12306041 | archive-date=23 January 2012 }}</ref>

On April 25, 1997, due to a combination of human error and a software bug, an incorrect routing table at MAI Network Service (a Virginia [[Internet service provider]]) propagated across backbone routers and caused major disruption to Internet traffic for a few hours.<ref>{{cite web|url=http://news.com/Router+glitch+cuts+Net+access/2100-1033_3-279235.html|title=Router glitch cuts Net access|date=1997-04-25|publisher=[[CNET]] News.com|access-date=2008-07-11|archive-date=2020-07-27|archive-url=https://web.archive.org/web/20200727110252/https://www.cnet.com/news/|url-status=dead}}</ref>

{{see also|AS 7007 incident|List of web host service outages}}