Editing Dial-up Internet access (section)

==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.