Editing Dial-up Internet access

{{Short description|Access to the Internet Via Telephone Line}}
[[File:One analog 56k modem and an ISDN modem from ELSA, one ISDN modem TKR FastLink.jpg|thumb|260x260px|An array of [[Modem|modems]] used to accept incoming calls for dialing-up to the Internet]]
{{Listen
| filename     = Dial up modem noises.ogg
| title        = "Dial up modem noises"
| description  = Typical noises of dial-up modem (North America and United Kingdom) while a modem is establishing connection with a local ISP-server in order to get access to the [[Internet|public Internet]].
| pos          = right
}}

'''Dial-up Internet access''' is a form of [[Internet access]] that uses the facilities of the [[public switched telephone network]] (PSTN) to establish a connection to an [[Internet service provider]] (ISP) by dialing a [[telephone number]] on a conventional [[telephone line]] which could be connected using an RJ-11 connector.<ref>{{cite book | url=https://books.google.com/books?id=GZFxBgAAQBAJ&dq=rj-11+dial+up&pg=PA67 | isbn=978-1-118-96769-0 | title=The Internet for Dummies | date=2 March 2015 | publisher=John Wiley & Sons }}</ref> Dial-up connections use [[modem]]s to decode audio signals into data to send to a [[Router (computing)|router]] or computer, and to encode signals from the latter two devices to send to another modem at the ISP.

Dial-up Internet reached its peak popularity during the [[dot-com bubble]] with the likes of ISPs such as [[Sprint Corporation|Sprint]], [[EarthLink]], [[MSN Dial-up]], [[NetZero]], [[Prodigy (online service)|Prodigy]], and America Online (more commonly known as [[AOL]]). This was in large part because [[broadband]] Internet did not become widely used until well into the 2000s. Since then, most dial-up access has been replaced by [[broadband]].

==History==
In 1979, [[Tom Truscott]] and [[Jim Ellis (computing)|Jim Ellis]], graduates of [[Duke University]], created an early predecessor to dial-up Internet access called the [[Usenet]]. The Usenet was a [[UNIX]] based system that used a dial-up connection to transfer data through telephone modems.<ref name="Hauben">{{cite book|last1=Hauben|first1=Michael|last2=Hauben|first2=Rhonda|title=Netizens: On the History and Impact of Usenet and the Internet|date=1997|publisher=IEEE Computer Society Press|location=Los Alamitos, CA|isbn=0-8186-7706-6|pages=161–200|edition=1st|url=http://www.columbia.edu/~rh120/|access-date=25 February 2017}}</ref> 

Dial-up Internet access has existed since the 1980s via public providers such as [[NSFNET]]-linked universities in the United States. In the United Kingdom, [[JANET]] linked academic users, including a connection to the [[ARPANET]] via [[University College London]], while [[Brunel University]] and the [[University of Kent]] offered dial-up UUCP to non-academic users in the late 1980s.<ref>{{Cite web|url=https://support.bbc.co.uk/support/history.html|title=BBC Internet Services - History|website=support.bbc.co.uk|access-date=2019-09-19}}</ref><ref name=":22">{{Cite web |last=Houlder |first=Peter |date=19 January 2007 |title=Starting the Commercial Internet in the UK |url=https://www.uknof.org.uk/uknof6/Houlder-History.pdf |url-status=dead |archive-url=https://web.archive.org/web/20200213100236/https://www.uknof.org.uk/uknof6/Houlder-History.pdf |archive-date=13 February 2020 |access-date=2020-02-12 |website=6th UK Network Operators' Forum}}</ref><ref name=":12">{{Cite web |last=Reid |first=Jim |date=3 April 2007 |title=Networking in UK Academia ~25 Years Ago |url=https://www.uknof.org.uk/uknof7/Reid-History.pdf |url-status=dead |archive-url=https://wayback.archive-it.org/all/20170507114646/https://www.uknof.org.uk/uknof7/Reid-History.pdf |archive-date=7 May 2017 |access-date=2020-02-12 |website=7th UK Network Operators' Forum}}</ref>

Commercial dial-up Internet access was first offered in 1989 in the US by the software development company Software Tool & Die, with their service called "[[The World (Internet service provider)|The World]]".  [[Sprint Corporation|Sprint]] and [[AT&T Internet|AT&T]] in 1992 also began offering internet access, along with [[Pipex]] in the United Kingdom.<ref>{{cite web |date=31 July 1992 |title=H-Net Discussion Networks – SprintLink Commercial Availability Announced (fwd) |url=http://h-net.msu.edu/cgi-bin/logbrowse.pl?trx=vx&list=edtech&month=9207&week=&msg=An61j4s0%2BR1UHNuEZOgGfw&user=&pw= |url-status=dead |archive-url=https://web.archive.org/web/20160305153637/http://h-net.msu.edu/cgi-bin/logbrowse.pl?trx=vx&list=edtech&month=9207&week=&msg=An61j4s0%2BR1UHNuEZOgGfw&user=&pw= |archive-date=5 March 2016 |access-date=16 October 2015 |website=h-net.msu.edu}}</ref><ref>{{Cite news|url=https://www.telegraph.co.uk/technology/connecting-britain/timeline-how-uk-got-connected/ |archive-url=https://ghostarchive.org/archive/20220112/https://www.telegraph.co.uk/technology/connecting-britain/timeline-how-uk-got-connected/ |archive-date=2022-01-12 |url-access=subscription |url-status=live|title=How the UK got connected|date=2016-10-27|work=The Telegraph|access-date=2019-09-17|language=en-GB|issn=0307-1235|postscript=none}}{{cbignore}}; {{cite web|url=http://www.gtnet.gov.uk/corporate/about/|title=About PIPEX|publisher=GTNet|access-date=2012-06-30|archive-url=https://web.archive.org/web/20121101022035/http://www.gtnet.gov.uk/corporate/about/|archive-date=2012-11-01|url-status=dead}}</ref> After the introduction of commercial [[broadband]] in the late 1990s,<ref>{{Cite web|url=http://home.bt.com/tech-gadgets/internet/broadband/who-invented-broadband-11364284589900|title=Who invented broadband? How copper telephone lines became high-speed internet connections|date=25 July 2018|website=BT|access-date=19 September 2019|archive-date=24 January 2021|archive-url=https://web.archive.org/web/20210124100319/http://home.bt.com/tech-gadgets/internet/broadband/who-invented-broadband-11364284589900|url-status=dead}}</ref> dial-up became less popular. In the United States, the availability of dial-up Internet access dropped from 40% of Americans in the early 2000s to 3% in the early 2010s.<ref>{{Cite web |last=Brenner |first=Joanna |title=3% of Americans use dial-up at home |url=https://www.pewresearch.org/short-reads/2013/08/21/3-of-americans-use-dial-up-at-home/ |access-date=2024-01-21 |website=Pew Research Center |date=21 August 2013 |language=en-US}}</ref> It is still used where other forms are not available or where the cost is too high, as in some rural or remote areas.<ref>{{Cite news |date=2017-04-01 |title=What's it like to use AOL dial-up internet in 2017? |url=https://www.digitaltrends.com/cool-tech/aol-dial-up-a-relic-of-the-past/ |access-date=2018-06-03 |work=Digital Trends |language=en-US}}</ref><ref name="cbc.ca">{{Cite news |title=Dial-up internet used by hundreds of thousands in Canada {{!}} CBC News |url=http://www.cbc.ca/news/technology/dial-up-internet-used-by-hundreds-of-thousands-in-canada-1.1202392 |access-date=2018-06-03 |work=CBC |language=en-US}}</ref><ref>{{Cite web |last=Cossick |first=Samantha |date=2019-06-20 |title=Dial-up Internet And Our Fondness For The First Internet Connection |url=https://www.allconnect.com/blog/enduring-interest-dial-up-internet |access-date=2024-01-21 |website=Allconnect |language=en-US}}</ref><ref>{{Cite web |title=U.S. household dial-up internet connection usage 2019 |url=https://www.statista.com/statistics/185532/us-household-dial-up-internet-connection-usage-by-state-2009/ |access-date=2024-01-21 |website=Statista |language=en}}</ref>

== Modems ==
{{main|Dial-up modem}}
[[File:Modem-bank-1.jpg|thumb|Banks of modems used by an ISP to provide dial-up Internet service]]
Because there was no technology to allow different carrier signals on a telephone line at the time, dial-up Internet access relied on using audio communication. A modem would take the digital data from a computer, [[modulation|modulate]] it into an audio signal and send it to a receiving modem. This receiving modem would [[demodulate]] the signal from modulating analogue noise and demodulating it back into digital data for the computer to process via a modem that would decode the data, and send it to the computer.<ref name=":0">{{Cite web|last=Quine|first=Alison|date=2008-01-28|title=Modem (Modulation/Demodulation) Definition|url=https://www.itprc.com/modem-modulationdemodulation-definition/|access-date=2021-06-14|website=ITPRC|language=en-US}}</ref>

The simplicity of this arrangement meant that people would be unable to use their phone line for verbal communication until the Internet call was finished.

The Internet speed using this technology can drop to 21.6 [[kbit/s]] or less. Poor condition of the telephone line, high noise level and other factors all affect dial-up speed. For this reason, it is popularly called the 21600 Syndrome.<ref>{{cite web |url=http://www.usrmodem.ru/documents/articles/symbrate.shtml |title=СИHДРОМ 21600/V34 или Правда о том, как USR выбирает Symbol Rate |website=www.usrmodem.ru |access-date=11 January 2022 |archive-url=https://web.archive.org/web/20210715084533/http://www.usrmodem.ru/documents/articles/symbrate.shtml |archive-date=15 July 2021 |url-status=dead}}</ref><ref>{{Cite web|url=https://forum.ixbt.com/topic.cgi?id=32:796|title=Синдром 21600 как с ним бороться ? [1] - Конференция iXBT.com|website=forum.ixbt.com}}</ref>

==Availability==
Dial-up connections to the Internet require no additional [[infrastructure]] other than the [[telephone network]] and the modems and servers needed to make and answer the calls. Because telephone access is widely available, dial-up is often the only choice available for [[Rural internet|rural or remote]] areas, where [[broadband]] installations are not prevalent due to low population density and high infrastructure cost.<ref name="cbc.ca"/> 

A 2008 [[Pew Research Center]] study stated that only 10% of US adults still used dial-up Internet access. The study found that the most common reason for retaining dial-up access was high broadband prices. Users cited lack of infrastructure as a reason less often than stating that they would never upgrade to broadband.<ref>{{cite news |url=http://www.foxnews.com/story/0,2933,375624,00.html |title=Many Dial-Up Users Don't Want Broadband |access-date=2009-11-03 |agency=Associated Press |publisher=[[Fox News Channel]] | date=2008-07-07}}</ref> That number had fallen to 6% by 2010,{{r|todd20120215}} and to 3% by 2013.<ref>{{citation | title=3% of Americans use dial-up at home |url=http://www.pewresearch.org/fact-tank/2013/08/21/3-of-americans-use-dial-up-at-home/ | work=Pew Research Center|date=21 August 2013 | access-date=2013-11-28}}</ref>

A survey conducted in 2018 estimated that 0.3% of Americans were using dial-up by 2017.<ref>{{cite web |title=Percentage of households in the United States in 2017, by internet subscription |url=https://www.statista.com/statistics/185602/broadband-and-dial-up-internet-connection-usage-in-the-us/ |website=statista.com |publisher=Joseph Johnson |access-date=17 February 2021}}</ref>

The [[Canadian Radio-television and Telecommunications Commission|CRTC]] estimated that there were 336,000 Canadian dial-up users in 2010.<ref>{{Cite news|url=http://www.cbc.ca/news/technology/dial-up-internet-used-by-hundreds-of-thousands-in-canada-1.1202392|title=Dial-up internet used by hundreds of thousands in Canada {{!}} CBC News|work=CBC|access-date=2018-06-03|date=2012-05-12|language=en-US}}</ref>

==Replacement by broadband==
Broadband Internet access via [[cable Internet access|cable]], [[digital subscriber line]], [[wireless broadband]], [[mobile broadband]], [[Satellite Internet access|satellite]] and [[Fiber to the x|FTTx]] has replaced dial-up access in many parts of the world. Broadband connections typically offer speeds of 700 [[kbit/s]] or higher for two-thirds more than the price of dial-up on average.<ref name="todd20120215">{{cite web | url=http://www.post-gazette.com/pg/12046/1210209-28.stm | title=Plenty of Internet users cling to slow dial-up connections | work=Pittsburgh Post-Gazette | date=2012-02-15 | access-date=February 17, 2012 | author=Todd, Deborah M.}}</ref> In addition, broadband connections are always on, thus avoiding the need to connect and disconnect at the start and end of each session. Broadband does not require the exclusive use of a phone line, and thus one can access the Internet and at the same time make and receive voice phone calls without having a second phone line.

However, many rural areas remain without high-speed Internet, despite the eagerness of potential customers. This can be attributed to population, location, or sometimes ISPs' lack of interest due to little chance of profitability and high costs to build the required infrastructure. Some dial-up ISPs have responded to the increased competition by lowering their rates and making dial-up an attractive option for those who merely want email access or basic Web browsing.<ref>{{cite news |url=https://blogs.wsj.com/digits/2009/02/27/could-you-go-back-to-dial-up/ |title=Could You Go Back to Dial-Up? - Digits - WSJ.com  |access-date=2009-02-27 |work=Wall Street Journal|publisher=Dow Jones | first=Andrew | last=LaVallee | date=2009-02-27}}</ref><ref>{{cite news |url=http://www.foxnews.com/story/0,2933,500686,00.html |title=Recession Has Many Holding on to Dirt-Cheap Dial-Up  |access-date=2009-02-27 |work=Fox News | date=2009-02-26}}</ref>

Dial-up has seen a significant fall in usage, with the potential to cease to exist in future as more users switch to broadband.<ref>{{Cite web |title=End of an era, KPN stops its last internet dial-in number |url=https://www.overons.kpn/nieuws/en/end-of-an-era-kpn-stops-its-last-internet-dial-in-number/ |access-date=2025-03-23 |website=End of an era, KPN stops its last internet dial-in number |language=en}}</ref> In 2013, only about 3% of the U.S population used dial-up, compared to 30% in 2000.<ref>{{cite web |title= Home Broadband 2013 |work= Pew Internet & American Life Project |url= http://pewinternet.org/Reports/2013/Broadband.aspx |access-date= April 20, 2015 |archive-date= February 9, 2014 |archive-url= https://web.archive.org/web/20140209214950/http://www.pewinternet.org/Reports/2013/Broadband.aspx |url-status= dead }}</ref> One contributing factor is the bandwidth requirements of newer computer programs, like [[operating systems]] and [[antivirus]] software, which automatically download sizeable updates in the background when a connection to the Internet is first made. These background downloads can take several minutes or longer and, until all updates are completed, they can severely impact the amount of bandwidth available to other applications like Web browsers.

Since an "always on" broadband is the norm expected by most newer applications being developed,{{Citation needed|date=November 2019}} this automatic background downloading trend is expected to continue to eat away at dial-up's available bandwidth to the detriment of dial-up users' applications.<ref>Kaspersky Technical Support website [search "dial up" slow] July 17, 2015</ref> Many newer websites also now assume broadband speeds as the norm, and when connected to with slower dial-up speeds may drop (timeout) these slower connections to free up communication resources. On websites that are designed to be more dial-up friendly, use of a [[reverse proxy]] prevents dial-ups from being dropped as often but can introduce long wait periods for dial-up users caused by the buffering used by a reverse proxy to bridge the different data rates.

Despite the rapid decline, dial-up Internet still exists in some rural areas, and many areas of developing and underdeveloped nations, although wireless and satellite broadband are providing faster connections in many rural areas where fibre or copper may be uneconomical.{{Citation needed|date=December 2020}}

In 2010, it was estimated that there were 800,000 dial-up users in the UK. [[BT Group|BT]] turned off its dial-up service in 2013.<ref>{{Cite news |date=2013-08-31 |title=BT turns off dial-up internet access service |language=en-GB |work=BBC News |url=https://www.bbc.com/news/technology-23877364 |access-date=2022-03-19}}</ref>

In 2012, it was estimated that 7% of Internet connections in New Zealand were dial-up. [[One NZ]] (formerly Vodafone) turned off its dial-up service in 2021.<ref>{{Cite web |date=2017-04-15 |title=Dial-up and broadband Internet connections in New Zealand - Figure.NZ |url=https://figure.nz/chart/e7H4mmtk4iNoJZ0f |access-date=2023-11-07 |archive-url=https://web.archive.org/web/20170415170045/https://figure.nz/chart/e7H4mmtk4iNoJZ0f |archive-date=2017-04-15 }}</ref><ref>{{Cite web |date=2021-05-26 |title=Dial-up internet service closing on Monday as Vodafone helps customers onto new tech |url=https://media.one.nz/news/technology/dialup |access-date=2023-11-07 |website=Media - One NZ |language=en}}</ref>

==Performance==
[[File:Dial up modem noises explained final.png|thumbnail|An example handshake of a dial-up modem]]

Modern dial-up modems typically have a maximum theoretical transfer speed of 56&nbsp;kbit/s (using the [[ITU-T V.90|V.90]] or [[ITU-T V.92|V.92]] [[Communications protocol|protocol]]), although in most cases, 40–50&nbsp;kbit/s is the norm. Factors such as phone [[line noise]] as well as the quality of the modem itself play a large part in determining connection speeds.{{Citation needed|date=November 2019}}

Some connections may be as low as 21.6&nbsp;kbit/s in extremely noisy environments, such as in a hotel room where the phone line is shared with many extensions, or in a rural area, many kilometres from the phone exchange. Other factors such as long loops, [[loading coil]]s, [[pair gain]], [[electric fence]]s (usually in rural locations), and [[digital loop carrier]]s can also slow connections to 21.6&nbsp;kbit/s or lower. Because of this, it was nicknamed "21600 Syndrome".


Note that the values given are maximum values, and actual values may be slower under certain conditions (for example, noisy phone lines).<ref>{{cite web |title=Winbox |url=https://winboxplay.my/ |archive-url=https://web.archive.org/web/20230522042122/https://winboxplay.my/ |url-status=usurped |archive-date=May 22, 2023 |access-date=2024-08-03 |website=Winboxplay.my |publisher=International Entertainment Union}}</ref>

{| style="text-align:right;"
|-
! style="text-align:right;"| Connection
! [[Bitrate]]
|-
| style="text-align:left;" colspan="6"| 
|-
| 110 baud ([[Bell 101]]) || 0.11 [[kbit/s]] ||align="left" | (110 bits per second)
|-
| 300 baud ([[Bell 103]] or [[ITU-T V.21|V.21]]) || 0.3 kbit/s
|-
| 1200 baud ([[Bell 212A]] or [[ITU-T V.22|V.22]]) || 1.2 kbit/s
|-
| 2400 baud ([[ITU-T V.22bis|V.22bis]]) || 2.4 kbit/s
|-
| 2400 baud ([[ITU-T V.26bis|V.26bis]]) || 2.4 kbit/s
|-
| 4800 baud ([[ITU-T V.27ter|V.27ter]]) || 4.8 kbit/s
|-
| 9600 baud ([[ITU-T V.32|V.32]]) || 9.6 kbit/s
|-
| 14.4 kbit/s ([[ITU-T V.32bis|V.32bis]]) || 14.4 kbit/s
|-
| 28.8 kbit/s ([[ITU-T V.34|V.34]]) || 28.8 kbit/s
|-
| 33.6 kbit/s ([[ITU-T V.34|V.34]]) || 33.6 kbit/s
|-
| 56k kbit/s ([[ITU-T V.90|V.90]]) || 56.0 to 33.6 kbit/s
|-
| 56k kbit/s ([[ITU-T V.92|V.92]]) || 56.0 to 48.0 kbit/s
|-
| [[ISDN]] || 64.0 to 128.0 kbit/s
|-
| Hardware compression ([[ITU-T V.92|V.92]]/[[ITU-T V.44|V.44]])  || 56.0 to 320.0 kbit/s ||align="left"| (variable)
|-
| Server-side web compression                  || &nbsp;&nbsp;&nbsp;200.0 to 1000.0 kbit/s ||align="left"| (variable)
|}

<gallery mode="packed">
File:V.90_-_3Com_USR_-_56k.wav|V.90 - 3Com USR - 56k
File:V.90_-_RockWeller_-_56k.wav|V.90 - RockWeller - 56k
File:V.90_-_ZyXEL_Omni_56K.wav|ZyXEL Omni 56K
File:V.90_-_Momenta_56DSP.wav|V.90 - Momenta 56DSP
File:V.34_-_Sindrome_21600.wav|V.34 - Sindrome 21600
File:V.21_-_300-kbps_-_Helicopter.wav|V.80 - Helicopter
File:V.34_-_RockWeller_-_33.6k.wav|V.34 - RockWeller - 33.6k
File:V.92 - ElCom HSP PCI Fax modem 56k.wav|V.92 - ElCom HSP PCI Fax modem - 56k
</gallery>

{{Quote box
 |quote  = [The dial-up sounds are] a choreographed sequence that allowed these digital devices to piggyback on an analog telephone network. A phone line carries only the small range of frequencies in which most human conversation takes place: about three hundred to three thousand hertz. The modem works within these [telephone network] limits in creating sound waves to carry data across phone lines. '''What you're hearing is the way 20th century technology tunneled through a 19th century network'''; what you're hearing is how a network designed to send the noises made by your muscles as they pushed around air came to transmit ''anything'' [that can be] coded in zeroes and ones.
 |source = -Alexis Madrigal, paraphrasing Glenn Fleishman<ref>{{cite web |archive-url=https://web.archive.org/web/20150816010035/http://www.theatlantic.com/technology/archive/2012/06/the-mechanics-and-meaning-of-that-ol-dial-up-modem-sound/257816/ |archive-date=2015-08-16 |title=The Mechanics and Meaning of That Ol' Dial-Up Modem Sound |author=Alexis C. Madrigal |date=June 1, 2012 |work=[[The Atlantic]] |url=https://www.theatlantic.com/technology/archive/2012/06/the-mechanics-and-meaning-of-that-ol-dial-up-modem-sound/257816/}}</ref>
 |width  = 25%
 |align  = left
 |salign = right
}}
Analog telephone lines are digitally switched and transported inside a [[Digital Signal 0]] once reaching the telephone company's equipment. [[Digital Signal 0]] is 64&nbsp;kbit/s and reserves 8&nbsp;kbit/s for signaling information; therefore a 56&nbsp;kbit/s connection is the highest that will ever be possible with analog phone lines.

Dial-up connections usually have [[latency (engineering)|latency]] as high as 150 ms or even more, higher than many forms of broadband, such as cable or DSL, but typically less than satellite connections. Longer latency can make [[Videoconferencing|video conferencing]] and [[Online game|online gaming]] difficult, if not impossible. An increasing amount of Internet content such as [[streaming media]] will not work at dial-up speeds.

Video games released from the mid-1990s to the mid-2000s that utilized Internet access such as ''[[EverQuest]]'', ''[[Red Faction]]'', ''[[Warcraft 3]]'', ''[[Final Fantasy XI]]'', ''[[Phantasy Star Online]]'', ''[[Guild Wars]]'', ''[[Unreal Tournament]]'', ''[[Halo: Combat Evolved]]'', ''[[Audition Online|Audition]]'', ''[[Quake 3: Arena]]'', ''[[Starsiege: Tribes]]'' and ''[[Ragnarok Online]]'', etc., accommodated for 56k dial-up with limited [[data transfer]] between the game servers and user's personal computer. The first consoles to provide Internet connectivity, the [[Dreamcast]] and [[PlayStation 2]], supported dial-up as well as broadband. The [[GameCube]] could use dial-up and broadband connections, but this was used in very few games and required a separate adapter. The [[Xbox (console)|original Xbox]] exclusively required a broadband connection. Many computer and video games released since 2006 do not even include the option to use dial-up. However, there are exceptions to this, such as ''[[Vendetta Online]]'', which can still run on a dial-up modem.

===Using compression to exceed 56k===
The [[ITU-T V.42|V.42, V.42bis]] and [[ITU-T V.44|V.44 standards]] allow modems to accept compressed data at a rate faster than the line rate. These algorithms use [[data compression]] to achieve higher throughput.

For instance, a 53.3&nbsp;kbit/s connection with V.44 can transmit up to 53.3 × 6 = 320&nbsp;kbit/s if the offered data stream can be compressed that much. However, the compression ratio varies considerably. ZIP archives, [[JPEG]] images, [[MP3]], video, etc. are already compressed.<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=2008-02-18 |author=Pavel Mitronov |publisher=Pricenfees.com |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 |url-status=dead }}</ref> A modem might be sending compressed files at approximately 50&nbsp;kbit/s, uncompressed files at 160&nbsp;kbit/s, and pure text at 320&nbsp;kbit/s, or any rate in this range.<ref>{{cite web |url=http://fndcg0.fnal.gov/Net/modm8-94.txt |access-date=2008-02-18 |title=What You Need to Know about Modems |author=Karl Willdig |work=Fermilab Data Communications and Networking Group |publisher=Fermi National Accelerator Laboratory |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>

====Compression by the ISP====
{{Main|Web accelerator}}
As telephone-based Internet lost popularity by the mid-2000s, some Internet service providers such as TurboUSA, [[Netscape]], CdotFree, and [[NetZero]] started using data compression to increase the perceived speed. As an example, EarthLink advertises "surf the Web up to 7x faster" using a compression program on images, text/html, and SWF flash animations prior to transmission across the phone line.<ref>{{Cite web|url=http://www.earthlink.net/dialup/|title=EarthLink Dial-Up Internet service – fast, reliable dialup access nationwide.|website=www.earthlink.net|access-date=2017-01-12}}</ref>

The pre-compression operates much more efficiently than the on-the-fly compression of V.44 modems. Typically, website text is compacted to 5%, thus increasing effective throughput to approximately 1000&nbsp;kbit/s, and JPEG/GIF/PNG images are lossy-compressed to 15–20%, increasing effective throughput up to 300&nbsp;kbit/s.

The drawback of this approach is a loss in quality, where the graphics acquire [[compression artifacts]] taking on a blurry or colorless appearance. However, the transfer speed is dramatically improved. If desired, the user may choose to view uncompressed images instead, but at a much slower load rate. Since streaming music and video are already compressed at the source, they are typically passed by the ISP unaltered.

==Usage in other devices==
[[File:Series 2 tivo back.jpg|thumb|A [[TiVo Series2]] video recorder's back panel. The telephone socket, located near the cooling fan exhaust, is a way for the machine to download its required [[electronic program guide]] data.]]

Other devices, such as [[satellite receiver]]s and [[digital video recorder]]s (such as [[TiVo]]), have also used a dial-up connection using a household phone socket. This connection allowed to download data at request and to report usage (e.g. ordering [[pay-per-view]]) to the service provider. This feature did not require an [[Internet service provider]] account – instead, the device's internal modem dialed the server of the service provider directly. These devices may experience difficulties when operating on a [[VoIP]] line because the compression could alter the modem signal. Later, these devices moved to using an [[Ethernet]] connection to the user's Internet [[router (computing)|router]], which became a more convenient approach due to the growth in popularity of broadband.

==See also==
{{Portal|Internet}}
*[[Registered jack]]
*[[Ascend Communications]] made equipment for Dial-Up ISPs

==References==
{{reflist}}

{{Internet Access}}

{{DEFAULTSORT:Dial-Up Internet Access}}
[[Category:American inventions]]
[[Category:Internet access]]
[[Category:Web 1.0]]
[[Category:Obsolete technologies]]