Skype is a software application that allows users to make voice calls over the Internet. Calls to other users of the service and, in some countries, to free-of-charge numbers, are free, while calls to other landlines and
mobile phoneA mobile phone or mobile is a long-range, electronic device used for mobile telecommunications...
s can be made for a fee. Additional features include
instant messagingInstant messaging is a form of real-time communication between two or more people based on typed text. The text is conveyed via devices connected over a network such as the Internet.-Overview:...
,
file transferFile transfer is a generic term for the act of transmitting files over a computer network or the Internet. There are numerous ways and protocols to transfer files over a network. Computers which provide a file transfer service are often called file servers...
and video conferencing.
Skype was written by
EstoniaEstonia , officially the Republic of Estonia , is a country in Northern Europe. It is bordered to the north by the Gulf of Finland, to the west by the Baltic Sea, to the south by Latvia , and to the east by the Russian Federation...
-based developers
Ahti HeinlaAhti Heinla is Skype chief architect, investor and nature protector.He was an organizer of Let's Do It 2008, a civic action with 50,000 volunteers participating in cleaning up the countryside of Estonia in one day....
, Priit Kasesalu and
Jaan TallinnJaan Tallinn is an Estonian programmer who participated in the development of Skype and KaZaa.Jaan Tallinn is partner and co-founder of the development company Bluemoon...
, who had also originally developed
KazaaKazaa Media Desktop is a peer-to-peer file sharing application using the FastTrack protocol and owned by Sharman Networks....
. The Skype Group, founded by
SwedishSweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe...
-born
entrepreneurAn entrepreneur is a person who has possession of an enterprise, or venture, and assumes significant accountability for the inherent risks and the outcome. It is an ambitious leader who combines land, labor, and capital to often create and market new goods or services. ... The term is a loanword...
Niklas ZennströmNiklas Zennström is a Swedish entrepreneur.In 2001 Zennström, along with Janus Friis, co-founded Kazaa Media Desktop the peer-to-peer file sharing application. In 2002, Zennström and Friis created Skype the peer-to-peer Internet telephony network...
and the Dane
Janus FriisJanus Friis is a Danish entrepreneur best known for co-founding the file-sharing application KaZaA, and the peer-to-peer telephony application Skype. In September 2005, he and his partner Niklas Zennström sold Skype to eBay for $2.6B...
, has its headquarters in
LuxembourgLuxembourg , officially the Grand Duchy of Luxembourg , is a small, landlocked country in western Europe, bordered by Belgium, France, and Germany...
, with offices in
London[]London is the capital of England and the United Kingdom. It has been a major settlement for two millennia, and the history of London goes back to its founding by the Romans, when it was named Londinium. London's core, the ancient City of London, the 'square mile', retains its medieval boundaries...
,
TallinnTallinn is the capital and largest city of Estonia. It occupies a surface of in which 405,867 inhabitants live. It is situated on the northern coast of the country, on the banks of the Gulf of Finland, south of Helsinki.-Historical names:...
,
TartuFor the French captain, see Jean-François TartuTartu is the second largest city of Estonia. In contrast to Estonia's political and financial capital Tallinn, Tartu is often considered the intellectual and cultural hub, especially since it is home to Estonia's oldest and most renowned university....
,
Stockholm' is the capital and largest city of Sweden. It is the site of the national Swedish government, the Riksdag , and the official residence of the Swedish Monarch as well as the prime minister. The Monarch resides at Drottningholm Palace outside of Stockholm since 1980 and uses the Royal Palace of...
,
PraguePrague is the capital and largest city of the Czech Republic. Nicknames for Prague have included "the mother of cities" , "city of a hundred spires", or Stověžatá Praha in Czech and "the golden city" or Zlaté město in Czech.Situated on the River Vltava in central Bohemia, Prague has been the...
, and
San Jose, CaliforniaSan Jose or San José is the third-largest city in California and the tenth-largest in the United States. The county seat of Santa Clara County, it is located at the southern end of the San Francisco Bay Area, a region commonly referred to as Silicon Valley...
.
One of the initial names for the project was "Sky peer-to-peer", which was then abbreviated to "Skyper". However, some of the domain names associated with "Skyper" were already taken. Dropping the final "r" left the current title "Skype", for which domain names were available.
Skype has experienced rapid growth in popular usage since the launch of its services. The company was acquired by
eBayeBay Inc. is an American Internet company that manages eBay.com, an online auction and shopping website in which people and businesses buy and sell a broad variety of goods and services worldwide. A majority of the sales take place through a set-time auction format, but subsequent methods include...
in September 2005 for $2.6 billion. eBay has written Skype down to $1.7 billion on its books and announced a public stock offering for 2010 to spin Skype off as a separate company. Some media outlets have characterized the proposed sale and ongoing provision of Skype as being under threat, because of a software licensing dispute with the original creators. On September 1, 2009, a group of investors led by
Silver LakeSilver Lake is an US-based private equity firm focused on leveraged buyout and growth capital investments in technology, technology-enabled and related industries...
bought 65% of Skype for $1.9 billion.
Features
Skype allows users to communicate by both voice, and more traditional textual instant messaging. Voice chat allows both calling a single user and conference calling. It uses a proprietary codec. Skype's text chat client allows group chats, emoticons, storing chat history, offline messaging and (in recent versions) editing of previous messages. The usual gamut of features familiar to instant messaging users - such as user profiles, online status indicators, and so on - is also included.
SkypeIn allows Skype users to receive calls on their computers dialed by regular phone subscribers to a local Skype phone number; local numbers are available for
AustraliaAustralia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the continental mainland , the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans...
,
BrazilBrazil , officially the Federative Republic of Brazil , is a country in South America. It is the fifth largest country by geographical area, occupying nearly half of South America, the fifth most populous country, and the fourth most populous democracy in the world. Bounded by the Atlantic Ocean...
,
ChileChile, officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...
,
ColombiaColombia , officially the Republic of Colombia , is a constitutional republic in northwestern South America. Colombia is bordered to the east by Venezuela and Brazil; to the south by Ecuador and Peru; to the north by the Caribbean Sea; to the northwest by Panama; and to the west by the Pacific Ocean...
,
DenmarkDenmark is a Scandinavian country in Northern Europe and the senior member of the Kingdom of Denmark. It is the southernmost of the Nordic countries; southwest of Sweden and south of Norway, and it is bordered to the south by Germany. Denmark borders both the Baltic and the North Sea...
, the
Dominican RepublicThe Dominican Republic is a nation on the island of Hispaniola, part of the Greater Antilles archipelago in the Caribbean region. The western third of the island is occupied by the nation of Haiti, making Hispaniola one of two Caribbean islands that are occupied by two countries...
,
EstoniaEstonia , officially the Republic of Estonia , is a country in Northern Europe. It is bordered to the north by the Gulf of Finland, to the west by the Baltic Sea, to the south by Latvia , and to the east by the Russian Federation...
,
FinlandFinland , officially the Republic of Finland
, is a Nordic country and democracy situated in the Fennoscandian region of northern Europe. It borders Sweden on the west, Russia on the east, and Norway on the north, while Estonia lies to its south across the Gulf of Finland...
,
FranceFrance , officially the French Republic , is a country located in Western Europe, with several overseas islands and territories located on other continents. Metropolitan France extends from the Mediterranean Sea to the English Channel and the North Sea, and from the Rhine to the Atlantic Ocean...
,
GermanyGermany , officially the Federal Republic of Germany , is a country in Central Europe. It is bordered to the north by the North Sea, Denmark, and the Baltic Sea; to the east by Poland and the Czech Republic; to the south by Austria and Switzerland; and to the west by France, Luxembourg, Belgium,...
,
Hong KongHong Kong , officially the Hong Kong Special Administrative Region, is a highly autonomous territory of the People's Republic of China, facing Guangdong to the north and the South China Sea to the east, west and south...
,
HungaryHungary , in English officially the Republic of Hungary , is a landlocked country in the Carpathian Basin of Central Europe, bordered by Austria, Slovakia, Ukraine, Romania, Serbia, Croatia, and Slovenia. Its capital is Budapest. Hungary is a member of OECD, NATO, EU, V4 and is a Schengen state...
,
IrelandIreland is the third-largest island in Europe and the twentieth-largest island in the world. It lies to the north-west of continental Europe and is surrounded by hundreds of islands and islets. To the east of Ireland, separated by the Irish Sea, is the island of Great Britain...
,
ItalyItaly , officially the Italian Republic , is a country located on the Italian Peninsula in Southern Europe and on the two largest islands in the Mediterranean Sea, Sicily and Sardinia. Italy shares its northern, Alpine boundary with France, Switzerland, Austria and Slovenia...
,
Japanis an island country in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, People's Republic of China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
,
MexicoThe United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
,
New ZealandNew Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses , and numerous smaller islands, most notably Stewart Island/Rakiura and the Chatham Islands. The indigenous Māori named New Zealand Aotearoa, commonly translated as The Land of the Long White Cloud...
,
PolandPoland , officially the Republic of Poland , is a country in Central Europe . Poland is bordered by Germany to the west; the Czech Republic and Slovakia to the south; Ukraine, Belarus and Lithuania to the east; and the Baltic Sea and Kaliningrad Oblast, a Russian exclave, to the north...
,
RomaniaRomania is a country located in Southeastern and Central Europe, North of the Balkan Peninsula, on the Lower Danube, within and outside the Carpathian arch, bordering on the Black Sea. Almost all of the Danube Delta is located within its territory...
,
South AfricaThe Republic of South Africa is a country located at the southern tip of Africa, with a coastline on the Atlantic and Indian Oceans. To the north lie Namibia, Botswana and Zimbabwe, to the east are Mozambique and Swaziland, while Lesotho is an independent country surrounded by South Africa.Modern...
,
South KoreaSouth Korea, officially the Republic of Korea and often simply referred to as Korea, is a country in East Asia, located on the southern half of the Korean Peninsula. It is neighbored by China to the west, Japan to the east, and North Korea to the north. Its capital is Seoul, the second largest...
,
SwedenSweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe...
,
SwitzerlandSwitzerland , officially the Swiss Confederation , is a federal republic consisting of 26 states named cantons, with Bern as the seat of the federal authorities...
, the
NetherlandsThe Netherlands is a country in Northwestern Europe, constituting the major portion of the Kingdom of the Netherlands. It is a parliamentary democratic constitutional monarchy. The Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east...
, the
United KingdomThe United Kingdom of Great Britain and Northern Ireland is a sovereign state located off the northwestern coast of continental Europe. It is an island country, spanning an archipelago including Great Britain, the northeastern part of Ireland, and many small islands...
, and the
United StatesThe United States of America is a federal constitutional republic comprising fifty states and a federal district...
. A Skype user can have local numbers in any of these countries, with calls to the number charged at the same rate as calls to fixed lines in the country. Some jurisdictions, including France, Germany and South Africa, forbid the registration of their telephone numbers to anyone without a physical presence or residency in the country..
Video conferencing between two users was introduced in January 2006 for the
WindowsMicrosoft Windows is a series of software operating systems and graphical user interfaces produced by Microsoft. Microsoft first introduced an operating environment named Windows in November 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces...
and
Mac OS XMac OS X is a line of computer operating systems developed, marketed, and sold by Apple Inc., and since 2002 has been included with all new Macintosh computer systems...
platform clients. Skype 2.0 for
LinuxLinux is a generic term referring to Unix-like computer operating systems based on the Linux kernel. Their development is one of the most prominent examples of free and open source software collaboration; typically all the underlying source code can be used, freely modified, and redistributed,...
, released on March 13, 2008, also features support for video conferencing.
Skype for Windows, starting with version 3.6.0.216, supports "High Quality Video" with quality and features,
e.g., full-screen and screen-in-screen modes, similar to those of mid-range videoconferencing systems. Skype audio conferences currently support up to 25 people at a time, including the host.
A discontinued feature called "Skypecasting" allowed recordings of Skype
voice over IPVoice over Internet Protocol is a general term for a family of transmission technologies for delivery of voice communications over IP networks such as the Internet or other packet-switched networks...
voice calls and
teleconferenceA teleconference or teleseminar is the live exchange and mass articulation of information among several persons and machines remote from one another but linked by a telecommunications system...
s to be used as podcasts, which allow audio or video content to be syndicated over the Internet. Skype launched its
"Skypecasts Beta" service in 2006. It remained in beta until its end. Skypecasts hosted public conference calls, up to 100 people at a time. Unlike ordinary Skype p2p conference calls, Skypecasts supported moderation features suitable for panel discussions, lectures, and town hall forums. Skype operated a directory of public Skypecasts. On August 26, 2008, Skype announced that Skypecasts would be discontinued beginning September 1, 2008. Skypecasts were shut down without any concrete explanation on 1 September 2008 at 12:00 UTC.
Skype does not provide the ability to call emergency numbers such as 911 in the United States and Canada, 000 in Australia, 112 in Europe, or 999 in the UK. The FCC has ruled that, for the purposes of section 255 of the
Telecommunications ActThe Telecommunications Act of 1996 was the first major overhaul of United States telecommunications law in nearly 62 years, amending the Communications Act of 1934.-Prior regime:...
, Skype is not an "interconnected VoIP provider". As a result, the U.S.
National Emergency Number AssociationThe National Emergency Number Association is an organization whose mission it is to foster the technological advancement, availability, and implementation of a universal emergency telephone number system. In carrying out its mission, NENA promotes research, planning, training and education...
recommends that all VoIP users have an analog line available as a backup.
Skype Name
Registered users of Skype are identified by a unique
Skype Name. Users may be listed in the Skype directory.
Skype clients applications and devices
- On April 24, 2008, Skype announced that they offer Skype on around 50 mobile phones.
- On October 29, 2007, Skype launched its own mobile phone under the brand name 3 Skypephone
The 3 Skypephone series is a range of 3G mobile phones made as a global project by the 3 network. The project was initiated by the 3's global handset team, some of who later went on to found the new mobile phone company INQ. The phones are sold in Australia, Austria, Denmark, Italy, Ireland,...
, which runs a BREWBREW is an application development platform created by QUALCOMM for mobile phones. It was originally developed for CDMA handsets, but has since been ported to other air interfaces including GSM/GPRS. BREW is a software platform that can download and run small programs for playing games, sending...
OS.
- Skype is available for the N800
The Nokia N800 Internet Tablet is a wireless Internet appliance from Nokia, originally announced at the Las Vegas CES 2007 Summit in January 2007. N800 allows the user to browse the Internet and communicate using Wi-Fi networks or with mobile phone via Bluetooth. The N800 was developed as the...
and N810The Nokia N810 Internet Tablet is an Internet appliance from Nokia, announced on 17 October, 2007 at the Web 2.0 Summit in San Francisco. Despite Nokia's strong association with cellular products, the N810 is not a phone, but instead allows the user to browse the Internet and communicate using...
Internet Tablets, which use the Linux Maemo environment.
- Skype is available on both the Sony mylo
The My Life Online is a device created and marketed by Sony for portable instant messaging and other Internet-based communications, browsing Internet web sites and playback and sharing of media files. The pocket-sized, tablet-shaped handheld device has a screen which slides up to reveal a QWERTY...
COM-1 and newer COM-2 models.
- Skype is available for the PSP
The PlayStation Portable is a handheld game console manufactured and marketed by Sony Computer Entertainment. Development of the console was announced during E3 2003, and it was unveiled on May 11, 2004 at a Sony press conference before E3 2004...
(PlayStation Portable) Slim and Lite with firmware version 3.90 or higher, but the user needs to purchase one of three microphone input peripherals.
- The new PSP-3000 has a built in microphone which allows communication without the Skype peripheral
- Skype is available on mobile devices running Windows Mobile
Windows Mobile is a compact operating system developed by Microsoft, and designed for use in smartphones and mobile devices.It is based on Windows CE, and features a suite of basic applications developed using the Microsoft Win32 API. It is designed to be somewhat similar to desktop versions of...
.
- The official Symbian
The Symbian platform is an open source operating system for mobile devices. It was created by merging and integrating software assets contributed by Nokia, NTT DoCoMo, and Sony Ericsson, including Symbian OS, the S60, UIQ and MOAP user interfaces....
version was under development in 2006, but was not released.
- Official Skype support is available as part of X-Series
X-Series from 3 is a mobile broadband offering from 3. It is priced like fixed line broadband. X-Series customers are charged a fixed monthly subscription, which in addition to ordinary calling minutes and texts, includes X-Series mobile broadband services, including normal internet access when...
together with mobile operator 3. However this uses a regular mobile phone call and iskoot to a Skype gateway, rather than mobile internet. Other companies produce dedicated Skype phones which connect via WiFiWIFI is a radio station broadcasting a Variety radio format. Licensed to Florence, New Jersey, USA. The station is currently operated by Florence Broadcasting Partners, LLC.This station was previously owned by Real Life Broadcasting...
.
- Third party developers, such as Nimbuzz
Nimbuzz is a messaging service combining instant messaging, presence and VoIP. It interfaces with several popular messaging services such as Skype, Windows Live Messenger, Yahoo! Messenger, ICQ, Google Talk, AIM, GaduGadu, XMPP and Twitter as well social networks such as Facebook and...
and Fringfring is a peer-to-peer Mobile VoIP based internet telephony network founded by Avi Shechter, formerly co–CEO of ICQ and a VP at AOL co-founded by Boaz Zilberman and Alex Nerst. fring enables users to talk and chat using Skype, ICQ, Google Talk, MSN Messenger / Windows Live Messenger, AIM, Yahoo...
, have allowed Skype to run in parallel with several other competing VoIP/IM networks in any Symbian or Java environment. Nimbuzz has made Skype available to BlackBerryBlackBerry is a line of wireless handheld devices that was introduced in 1999 as a two-way pager. In 2002, the more commonly known smartphone BlackBerry was released, which supports push e-mail, mobile telephone, text messaging, internet faxing, web browsing and other wireless information services....
users.
- An official free Skype application for the iPhone OS
The iPhone OS, known as OS X iPhone in its early history, is the operating system developed by Apple Inc. for the iPhone and iPod touch. Like Mac OS X, from which it was derived, it uses the Darwin foundation. iPhone OS has four abstraction layers: the Core OS layer, the Core Services layer, the...
was released in the iTunes store on March 31 2009. However, some network operators do not allow Skype calls to be made over their 3G network, restricting it to WiFi use only.
History
- September 2002, investment from Draper Investment Company and at that time, original name was Skyper.
- April 2003, Skype.com and Skype.net domain names registered.
- August 2003, First public beta version released.
- September 2005, SkypeOut banned in South China.
- October 2005, eBay
eBay Inc. is an American Internet company that manages eBay.com, an online auction and shopping website in which people and businesses buy and sell a broad variety of goods and services worldwide. A majority of the sales take place through a set-time auction format, but subsequent methods include...
purchased Skype (Oct 14).
- December 2005, videotelephony introduced. In April 2006, Number of registered users reaches 100 million.
- October 2006, Skype 2.0 for Mac is released, the first full release of Skype with video for Macintosh.
- December 2006: Skype announces a new pricing structure as of January 18, 2007, with connection fees for all SkypeOut calls. Skype 3.0 for Windows is released.
- In March 2007, Skype 3.1 is released, adding some new features, including Skype Find and Skype Prime. Skype also released a 3.2 beta with a new feature called Send Money which allows users to send money via PayPal from one Skype user to another.
- August 2007, Skype 3.5 for Windows released with additions such as video in mood, inclusion of video content in chat, call transfer to another person or a group, auto-redial.
- August 15, 2007, Skype 2.7.0.49 (beta) for Mac OS X released adding availability of contacts in the Mac Address Book to the Skype contact list, auto redial, contact groups, public chat creation, and an in-window volume slider to the call window.
- August 16 / August 17, 2007, Skype users unable to connect to full Skype network in many countries. Skype reports the system-wide crash was the result of exceptional number of logins after a Windows patch reboot ("Patch Tuesday
Patch Tuesday is the second Tuesday of each month, the day on which Microsoft releases security patches.Starting with Windows 98, Microsoft included a "Windows Update" system, that would check for patches to Windows and its components which Microsoft would release intermittently...
").
- November 2007, Skype users are set to lose their 020 7 numbers after December 20, 2007.
- January 30, 2008, Skype released for the Sony
is a multinational conglomerate corporation headquartered in Minato, Tokyo, Japan, and one of the world's largest media conglomerates with revenue exceeding ¥ 7.730.0 trillion, or $78.88 billion U.S. . Sony is one of the leading manufacturers of electronics, video, communications, video game...
PSPThe PlayStation Portable is a handheld game console manufactured and marketed by Sony Computer Entertainment. Development of the console was announced during E3 2003, and it was unveiled on May 11, 2004 at a Sony press conference before E3 2004...
hand-held gaming system.
- March 13, 2008, Skype 2.0 for Linux released with support for videoconferencing.
- July 9, 2008, Skype 4.0 Beta is released, changing Skype into a full-screen application.
- September 1, 2008, Skype discontinues its SkypeCast service, citing difficulties in moderating chat rooms.
- September 8, 2008, The seventh season of the U.S. syndicated game show Who Wants To Be a Millionaire premieres, with a new Ask the Expert lifeline that uses Skype for video chat.
- September 30, 2008, Skype 4.0 Beta 2 released, introducing 'Compact mode', after user criticism of the new default full-screen mode.
- October 2, 2008: Analysis reveals TOM-skype sends content of text messages and encryption keys to monitoring servers.
- November 2008, Skype added internal monthly and daily usage caps on their SkypeOut subscriptions advertised as "Unlimited". Many users and observers have commented on the high rate of dropped calls, and the difficulty of reconnecting dropped calls. These are most common for video calls and free (PC to PC) calls.
- Feb 6, 2009, Skype 4.0 is released.
- March 2009, Skype launched Skype for SIP
The Session Initiation Protocol is a signaling protocol, widely used for controlling multimedia communication sessions such as voice and video calls over Internet Protocol . Other feasible application examples include video conferencing, streaming multimedia distribution, instant messaging,...
, a service aimed at business users. At the time of launch around 35% of Skype's users were business users.
- April 14, 2009, eBay announced plans to spin off of Skype through an initial public offering in 2010.
- August 1, 2009, Joltid files a motion with the US Securities and Exchange Commission, seeking to terminate a licensing agreement with eBay which allows eBay (and therefore Skype) to use the peer to peer communications technology that Skype is based on. If successful, this may cause a shutdown of Skype in its current form.
- August 27, 2009, Skype releases an update to their more than one year old Linux-client.
- September 1, 2009, eBay sells 65% of Skype to Index Ventures and Silver Lake Partners.
- Early September 2009, Skype shuts down the Extras developer program.
Usage and traffic
http://www.slideshare.net/earningreport/presentation-on-q1-2009-earning-report-of-ebay-inc
| Date |
Total user accounts
(in millions) |
Active users — daily presence
(in millions) |
Skype to Skype minutes
(in billions) |
SkypeOut minutes
(in billions) |
Revenue USD
(in millions) |
| Q4 2005 |
74.7 |
10.8 |
N/A |
N/A |
N/A |
| Q1 2006 |
94.6 |
15.2 |
6.9 |
0.7 |
35 |
| Q2 2006 |
113.1 |
16.6 |
7.1 |
0.8 |
44 |
| Q3 2006 |
135.9 |
18.7 |
6.6 |
1.1 |
50 |
| Q4 2006 |
171.2 |
21.2 |
7.6 |
1.5 |
66 |
| Q1 2007 |
195.5 |
23.2 |
7.7 |
1.3 |
79 |
| Q2 2007 |
219.6 |
23.9 |
7.1 |
1.3 |
90 |
| Q3 2007 |
245.7 |
24.2 |
6.1 |
1.4 |
98 |
| Q4 2007 |
276.3 |
27.0 |
11.9 |
1.6 |
115 |
| Q1 2008 |
309.3 |
31.3 |
14.2 |
1.7 |
126 |
| Q2 2008 |
338.2 |
32.0 |
14.8 |
1.9 |
136 |
| Q3 2008 |
370 |
33.7 |
16 |
2.2 |
143 |
| Q4 2008 |
405 |
36.5 |
20.5 |
2.6 |
145 |
| Q1 2009 |
443 |
42.2 |
23.6 |
2.9 |
153 |
| Q2 2009 |
483 |
– |
25.5 |
3.0 |
170 |
Users may have more than one account, and it is not possible to identify users with multiple accounts.
It was reported that 19,568,844 concurrent Skype users were online as of October 5, 2009.
As of January 2009, Skype is available for Android and over 100 Java enabled mobile phones.
As of January 2009, Skype is adding about 30 million subscribers a quarter.
The volume of international traffic routed via Skype is significant. It has become the largest international voice carrier. Computer-to-computer traffic between Skype users in 2005 was 2.9% of international carrier traffic in 2005 and about 4.4% of the total international traffic of 264 billion minutes in 2006. In 2008, about 8% of cross-border calls were carried by Skype.
Skype incorporates some features which tend to hide its traffic, but it is not specifically designed to thwart
traffic analysisTraffic analysis is the process of intercepting and examining messages in order to deduce information from patterns in communication. It can be performed even when the messages are encrypted and cannot be decrypted. In general, the greater the number of messages observed, or even intercepted and...
and therefore does not provide
anonymous communicationAn anonymous P2P communication system is a peer-to-peer distributed application in which the nodes or participants are anonymous or pseudonymous...
. Some researchers have been able to
watermarkDigital watermarking is the process of possibly irreversibly embedding information into a digital signal. The signal may be audio, pictures or video, for example. If the signal is copied, then the information is also carried in the copy....
the traffic so that it is identifiable even after passing through an
anonymizing networkThe Onion Router is a free software implementation of second-generation onion routing – a system which claims to enable its users to communicate anonymously on the Internet...
.
SkypeNOW! is a service that Skype offers in South Africa to customers with
VodafoneVodafone is a British mobile network operator, with its headquarters in Newbury, Berkshire, England, UK. It is the largest mobile telecommunications network company in the world by turnover, and has a market value of about £75 billion...
mobile service, which can enable Vodafone users to engage in Skype international voice calls wirelessly.
System and software
Skype uses a
proprietaryIn telecommunications, a proprietary protocol is a communications protocol owned by a single organization or individual.-Enforcement:Proprietors may enforce restrictions through patents and by keeping them trade secrets...
Internet telephony (VoIP) network, called the
Skype protocolSkype uses a proprietary Internet telephony network. The protocol has not been made publicly available by Skype and official applications using the protocol are closed-source. The main difference between Skype and other VoIP networks is that Skype operates on a peer-to-peer model, rather than...
. The protocol has not been made publicly available by Skype and official applications using the protocol are closed-source. Part of the Skype technology relies on the Global Index P2P protocol, belonging to the Joltid corporation. The main difference between Skype and standard VoIP clients is that Skype operates on a
peer-to-peerA peer-to-peer, commonly abbreviated to P2P, distributed network architecture is composed of participants that make a portion of their resources directly available to other network participants, without the need for central coordination instances...
model (originally based on the
KazaaKazaa Media Desktop is a peer-to-peer file sharing application using the FastTrack protocol and owned by Sharman Networks....
software), rather than the more usual
client-serverClient-server computing or networking is a distributed application architecture that partitions tasks or work loads between service providers and service requesters, called clients. Often clients and servers operate over a computer network on separate hardware...
model. The Skype user directory is entirely decentralized and distributed among the
nodesIn communication networks, a node is a connection point, either a redistribution point or a communication endpoint . The definition of a node depends on the network and protocol layer referred to...
of the network —
i.e., users' computers — allowing the network to scale very easily to large sizes (currently about 240 million users) without a complex centralized infrastructure costly to the Skype Group. The disadvantage of this approach is that Skype offers no interoperability with
SIPThe Session Initiation Protocol is a signaling protocol, widely used for controlling multimedia communication sessions such as voice and video calls over Internet Protocol . Other feasible application examples include video conferencing, streaming multimedia distribution, instant messaging,...
-based VoIP networks.
Many networking and security companies claim to detect and control Skype's protocol for enterprise and carrier applications. While the specific detection methods used by these companies are often private, Pearson's Chi-Square Test and stochastic characterization with Naïve Bayesian Classifiers are two approaches that were published in 2007.
Skype uses an array of different audio compression methods including
G.729G.729 is an audio data compression algorithm for voice that compresses digital voice in packets of 10 milliseconds duration. It is officially described as Coding of speech at 8 kbit/s using conjugate-structure algebraic-code-excited linear prediction ....
and
SVOPCSVOPC is a compression method for audio which is used by applications such as Skype. It is a lossy speech compression codec designed specifically towards communication channels suffering from packet loss...
. Skype added a Skype-created codec called
SILKSILK is an audio compression format and audio codec used by Skype. It is developed by Skype Limited. SILK is a replacement for the SVOPC codec.The SILK codec was a separate development branch from SVOPC and it has been under development for over 3 years....
to Skype for Windows 4 and other Skype clients. SILK is intended to be "lightweight and embeddable".
Skype securitySkype is a Voip system developed by Skype Technologies S.A., and owned by eBay. It is a peer-to-peer based network in which voice calls don’t pass through a central server...
is a
secure communicationWhen two entities are communicating with each other, and they do not want a third party to listen to their communication, then they want to pass on their message in such a way that no body else could understand their message. This is known as communicating in a secure manner or secure communication...
; encryption cannot be disabled, and is invisible to the user. Skype reportedly uses non-proprietary, widely trusted encryption techniques:
RSAIn cryptography, RSA is an algorithm for public-key cryptography. It is the first algorithm known to be suitable for signing as well as encryption, and one of the first great advances in public key cryptography...
for key negotiation and the
Advanced Encryption StandardIn cryptography, the Advanced Encryption Standard is an encryption standard adopted by the U.S. government. The standard comprises three block ciphers, AES-128, AES-192 and AES-256, adopted from a larger collection originally published as Rijndael. Each AES cipher has a 128-bit block size, with...
to encrypt conversations. Skype provides an uncontrolled registration system for users with absolutely no proof of identity. This permits users to use the system without revealing their identity to other users. It is trivial, of course, for anybody to set up an account using any name; the displayed caller's name is no guarantee of authenticity. A third party paper analyzing the security and methodology of Skype was presented at Black Hat Europe 2006. It analyzed Skype and found a number of security issues with the current security model.
Versions exist for
LinuxLinux is a generic term referring to Unix-like computer operating systems based on the Linux kernel. Their development is one of the most prominent examples of free and open source software collaboration; typically all the underlying source code can be used, freely modified, and redistributed,...
, Linux-based Maemo,
Mac OS XMac OS X is a line of computer operating systems developed, marketed, and sold by Apple Inc., and since 2002 has been included with all new Macintosh computer systems...
(Intel and PPC),
iPhone OSThe iPhone OS, known as OS X iPhone in its early history, is the operating system developed by Apple Inc. for the iPhone and iPod touch. Like Mac OS X, from which it was derived, it uses the Darwin foundation. iPhone OS has four abstraction layers: the Core OS layer, the Core Services layer, the...
(iPhone and iPod Touch),
Microsoft WindowsMicrosoft Windows is a series of software operating systems and graphical user interfaces produced by Microsoft. Microsoft first introduced an operating environment named Windows in November 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces...
(
2000Windows 2000 is a line of operating systems produced by Microsoft for use on business desktops, notebook computers, and servers. Released on February 17, 2000, it was the successor to Windows NT 4.0, and is the final release of Microsoft Windows to display the "Windows NT" designation...
,
XPWindows XP is a line of operating systems produced by Microsoft for use on personal computers, including home and business desktops, laptops, and media centers. The name "XP" is short for "eXPerience"...
,
VistaWindows Vista is a line of operating systems developed by Microsoft for use on personal computers, including home and business desktops, laptops, tablet PCs, and media center PCs...
,
Windows MobileWindows Mobile is a compact operating system developed by Microsoft, and designed for use in smartphones and mobile devices.It is based on Windows CE, and features a suite of basic applications developed using the Microsoft Win32 API. It is designed to be somewhat similar to desktop versions of...
), and even Sony's
PSPThe PlayStation Portable is a handheld game console manufactured and marketed by Sony Computer Entertainment. Development of the console was announced during E3 2003, and it was unveiled on May 11, 2004 at a Sony press conference before E3 2004...
.
Privacy
In an interview with Kurt Sauer, Chief Security Officer Skype, he said, "We provide a safe communication option. I will not tell you whether we listen or not." Skype's client uses an undocumented and proprietary protocol. The
Free Software FoundationThe Free Software Foundation is a non-profit corporation founded by Richard Stallman on 4 October 1985 to support the free software movement, a copyleft-based movement which aims to promote the universal freedom to distribute and modify computer software...
(FSF) is concerned by user privacy issues arising from using proprietary software and protocols and has made replacement for Skype one of their high priority projects. Security researchers Biondi and Desclaux have speculated that Skype may have a back door, since Skype sends traffic even when it is turned off and because Skype has taken extreme measures to obfuscate their traffic and functioning of their program. Several media sources have reported that at a meeting about the "Lawful interception of IP based services" held on 25 June 2008, high-ranking but not named officials at the Austrian interior ministry said that it was not a problem for them to listen in on Skype conversations. Austrian broadcaster ORF, citing minutes from the meeting, have reported that "the Austrian police are able to listen in on Skype connections". Skype declined to comment on the reports.
In the United States, the FCC has interpreted the
Communications Assistance for Law Enforcement ActThe Communications Assistance for Law Enforcement Act is a United States wiretapping law passed in 1994, during the presidency of Bill Clinton...
as requiring digital phone networks to allow wiretapping in the presence of an FBI warrant, in the same way as traditional phone service. Skype is not yet compliant with the act and has, so far, stated that it does not plan to comply. According to the ACLU, the Act is inconsistent with the original intent of the Fourth Amendment to the U.S. Constitution; more recently, the ACLU has expressed the concern that the FCC interpretation of the Act is incorrect.
On February 2009
EurojustEurojust is an agency of the European Union dealing with judicial co-operation.It is composed of national prosecutors, magistrates or police officers of equivalent competence from each of the EU states...
started working on
lawful interceptionLawful interception is obtaining communications network data pursuant to lawful authority for the purpose of analysis or evidence. Such data generally consist of signalling or network management information or in fewer instances, the content of the communications...
of Skype and VoIP.
Service in China
Since September 2007, users in China trying to download the Skype software have been redirected to the site of
TOMTOM Online is a mobile Internet company in China, operating the popular Chinese-language Internet portal and offering a variety of online and mobile services, including wireless internet and online advertising. The TOM Group is the majority shareholder...
, a joint venture between a Chinese wireless operator and Skype, from which a modified Chinese version can be downloaded. The TOM client participates in China's system of
Internet censorshipInternet censorship in the People's Republic of China is conducted under a wide variety of laws and administrative regulations. In accordance with these laws, more than sixty Internet regulations have been made by the People's Republic of China government, and censorship systems are vigorously...
, monitoring text messages between Skype users in China as well as messages exchanged with users outside the country. Niklas Zennström, then chief executive of Skype, told reporters that TOM "had implemented a text filter, which is what everyone else in that market is doing. Those are the regulations." He also stated: "One thing that’s certain is that those things are in no way jeopardising the privacy or the security of any of the users." In October 2008, it was reported that TOM had been saving the full message contents of some Skype text conversations on its servers, apparently focusing on conversations containing political issues such as
TibetTibet is a plateau region in Asia, north of the Himalayas. It is home to the indigenous Tibetan people, and to some other ethnic groups such as Monpas and Lhobas, and is now also inhabited by considerable numbers of Han Chinese people. Tibet is the highest region on earth, with an average...
,
CultCult may popularly refer to a religious group with relatively few adherents whose beliefs or practices are regarded by others as strange or sinister.The term "cult" was originally used to denote a system of ritual practices...
,
Falun GongFalun Gong is a system of beliefs and practices founded in China by Li Hongzhi in 1992. The practice emerged at the end of China's "qigong boom" as a form of qigong practice. Its teachings are influenced by both Taoism and Buddhism.The number of Falun Gong practitioners is unknown, and the group...
,
Taiwan independenceTaiwan independence is a political movement whose goal is primarily to create an independent and sovereign Republic of Taiwan out of the lands currently governed by the Republic of China and claimed by the People's Republic of China .This movement is supported by the Pan-Green Coalition in Taiwan...
and Chinese Communist Party. The saved messages contain
personally identifiable informationPersonally Identifiable Information , as used in information security, refers to information that can be used to uniquely identify, contact, or locate a single person or can be used with other sources to uniquely identify a single individual...
about the messages senders and recipients, including IP addresses, usernames, land line phone numbers, and the entire content of the text messages, including the time and date of each message. This information was also saved for Skype users outside China who were communicating with a TOM-Skype user. Because of a server misconfiguration, these log files were for a time accessible to the public.
Customer service
There have been complaints about Skype's poor customer support. As of September 2009, Skype does not provide any official means to contact customer support, apart from indirect assistance through its web portal only and contact email addresses. Skype is also unable to update user billing information. Skype credit expires 180 days after the last charged call . Users are notified via email before balances are removed, but some software issues have resulted in some users not receiving notification. The Skype application itself has no mechanism to indicate that the listed balance will expire soon.
Furthermore, Skype has been criticized for its policy that denies users the right to know release dates.
See also
- Presence information
In computer and telecommunications networks, presence information is a status indicator that conveys ability and willingness of a potential communication partner--for example a user--to communicate...
- Comparison of VoIP software
VoIP software is used to conduct telephone-like voice conversations across Internet Protocol based networks. VoIP stands for "Voice over IP". For residential markets, VoIP phone service is often cheaper than traditional public switched telephone network service and can remove geographic...
- Mobile VoIP
Mobile VoIP is an extension of mobility to a Voice over IP network.There are several methodologies by which a mobile handset can be integrated into a VoIP network. One implementation turns the mobile device into a standard SIP client, which then uses a data network to send and receive SIP...
- Comparison of instant messaging clients
The following tables compare general and technical information for a number of instant messaging clients. Please see the individual products' articles for further information. This article is not all-inclusive or necessarily up-to-date...
- Comparison of instant messaging protocols
- Secure communication
When two entities are communicating with each other, and they do not want a third party to listen to their communication, then they want to pass on their message in such a way that no body else could understand their message. This is known as communicating in a secure manner or secure communication...
- Unified communications
Unified communications is the integration of real-time communication services such as instant messaging , presence information, IP telephony, video conferencing, call control and speech control with non real-time communication services such as unified messaging...
External links