Skype
Screenshot Skype 3. 6 Beta running in Windows Vista
Developed by	Skype Limited
Initial release	August 2003
Stable release	3.8.0.139 (Windows), 2.7.0.330 (Mac OS X), 2.0.0.68 (Linux x86), 2.2.0.37 (Windows Mobile)  (April 29, 2008 (Windows), May 14, 2008 (Mac OS X), April 3, 2008 (Linux), May 9, 2008 (Windows Mobile)) [+/−]
Preview release	[1]  () [+/−]
OS	Cross-platform
Available in	multilingual
Genre	voice over IP / instant messaging/ videoconferencing
License	Freeware (with some paid features)
Website	http://www.skype.com/

Skype (IPA: [skaɪp]) is a software program that allows users to make telephone calls over the Internet. Windows Vista (ˈvɪstə is a line of Operating systems developed by Microsoft for use on Personal computers including home and business desktops A software developer is a person or organization concerned with facets of the software development process wider than design and coding a somewhat broader scope of Founding Skype was founded in 2003 by Niklas Zennstrom and Janus Friis, whose main intention was to develop a piece of software which would revolutionise telephone August 2003: January - February - March - April - May - June - July - August - A software release is the distribution whether public or private of an initial or new and upgraded version of a Computer software product Events 1429 - Joan of Arc arrives to relieve the Siege of Orleans. 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common Events 1264 - Battle of Lewes: Henry III of England is captured in France making Simon de Montfort the 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common Events 1043 - Edward the Confessor is crowned King of England. 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common Events 1457 BC - Battle of Megiddo (15th century BC between Thutmose III and a large Canaanite coalition under the King of 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common A software release is the distribution whether public or private of an initial or new and upgraded version of a Computer software product An operating system (commonly abbreviated OS and O/S) is the software component of a Computer system that is responsible for the management and coordination In computing cross-platform (also known as multi-platform) is a term used to refer to Computer software or computing methods and concepts that are implemented A language is a dynamic set of visual auditory or tactile Symbols of Communication and the elements used to manipulate them Computer software can be organized into categories based on common function type or field of use Voice-over-Internet protocol ( VoIP, vɔɪp is a protocol optimized for the transmission of voice through the Internet A videoconference (also known as a videoteleconference) is a set of interactive Telecommunication technologies which allow two or more locations to interact A software license (or software licence in commonwealth usage is a Legal instrument governing the usage or redistribution of copyright protected software Freeware is computer Software that is available for use at no cost or for an optional fee A website (alternatively web site or Web site, a back-construction from the Proper noun World Wide Web) is a collection of Web pages Voice-over-Internet protocol ( VoIP, vɔɪp is a protocol optimized for the transmission of voice through the Internet Calls to other users of the service are free of charge, while calls to landlines and cell phones can be made for a fee. A landline, main line or fixed-line is a Telephone line which travels through a solid medium either metal Wire or Optical fibre Additional features include instant messaging, file transfer and video conferencing. File transfer is a generic term for the act of transmitting files over a Computer network or the Internet. A videoconference (also known as a videoteleconference) is a set of interactive Telecommunication technologies which allow two or more locations to interact

It was created by entrepreneurs Niklas Zennström, Janus Friis, and a team of software developers based in Tallinn, Estonia. An entrepreneur is a person who has possession over a company enterprise, or Venture, and assumes significant accountability for the inherent risks and the outcome Niklas Zennström (born 1966) is a Swedish entrepreneur He first gained fame as the co-founder of the KaZaA Peer-to-peer File sharing Janus Friis (born 1976 is a Danish entrepreneur best known for co-founding the File-sharing application KaZaA, and the Peer-to-peer telephony Tallinn (historically known by the German, Swedish and Danish name Reval or the Polish name Rewal, among other names Estonia, officially the Republic of Estonia ( Eesti or Eesti Vabariik) is a Country in Northern Europe in the Baltic region ^[1] The Skype Group has its headquarters in Luxembourg, with offices in London, Tallinn, Tartu, Prague,^[2] and San Jose, California. Luxembourg (Groussherzogtum Lëtzebuerg Grand-Duché de Luxembourg Großherzogtum Luxemburg is a small Landlocked country in Western Europe, bordered by London ( ˈlʌndən is the capital and largest urban area in the United Kingdom. Tallinn (historically known by the German, Swedish and Danish name Reval or the Polish name Rewal, among other names Tartu is the second largest City of Estonia. In contrast to Estonia's political and financial capital Tallinn, Tartu is often considered the intellectual Prague (ˈprɑːg Praha (ˈpraɦa see also other names) is the Capital and Largest city of the Czech Republic.

Skype has experienced rapid growth in popular usage since the launch of its services. It was acquired by eBay in September 2005 for $2. eBay Inc is an American Internet company that manages eBaycom an Online auction and shopping Website in which people and businesses buy and PortalCurrent events News collections and sources WikipediaNews collections and sources. 6 billion.

Contents 1 Features 1.1 SkypeOut 1.2 SkypeIn 1.3 Videoconferencing 1.4 Skype on mobile devices 1.5 Security features 2 Issues 2.1 Security concerns 2.2 Skype service issues 2.3 Compliance with the Communications Assistance for Law Enforcement Act 2.4 Censorship in China 3 Company timeline of events 4 Usage and traffic 5 System and software 5.1 Detailed changelogs 5.2 Skype protocol 6 See also 7 References 8 External links

Features

Main article: Features of Skype

SkypeOut

SkypeOut allows Skype users to call traditional telephone numbers, including mobile telephones, for a fee which varies depending on location.

SkypeIn

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 Australia, Brazil, Chile,^[3] Denmark, the Dominican Republic, Estonia, Finland, France, Germany, Hong Kong, Ireland, Japan, Mexico, New Zealand,^[3] Poland, Romania, South Korea, Sweden, Switzerland, UK, and the United States. For a topic outline on this subject see List of basic Australia topics. |utc_offset = -2 to -4 |time_zone_DST = BRST |utc_offset_DST = -2 to -5 |cctld Chile, officially the Republic of Chile ( Spanish:) is a country in South America occupying a long and narrow Coastal strip wedged between the The Kingdom of Denmark ( ˈd̥ænmɑɡ̊ (archaic ˈd̥anmɑːɡ̊ commonly known as Denmark, is a country in the Scandinavian region of northern Europe The Dominican Republic ( Spanish: República Dominicana;) is a nation located in the Caribbean region and shares the island of Hispaniola with Estonia, officially the Republic of Estonia ( Eesti or Eesti Vabariik) is a Country in Northern Europe in the Baltic region Finland, officially the Republic of Finland ( is a Nordic country situated in the Fennoscandian region of northern Europe. This article is about the country For a topic outline on this subject see List of basic France topics. Germany, officially the Federal Republic of Germany ( ˈbʊndəsʁepuˌbliːk ˈdɔʏtʃlant is a Country in Central Europe. Hong Kong ( officially the Hong Kong Special Administrative Region, is a territory located on China 's south coast on the Pearl River Delta, and borders Ireland ( Irish: Éire, ˈeːrʲə is a country in north-western Europe. For a topic outline on this subject see List of basic Japan topics. The United Mexican States ( or commonly Mexico (ˈmɛksɪkoʊ () is a federal constitutional Republic in North America. New Zealand is an Island country in the south-western Pacific Ocean comprising two main landmasses (the North Island and the South Island Poland (Polska officially the Republic of Poland Romania ( dated: Rumania, Roumania South Korea, officially the Republic of Korea and often referred to as Korea ( Korean: 대한민국 tɛː "Sverige" redirects here For other uses see Sweden (disambiguation and Sverige (disambiguation. Switzerland (English pronunciation; Schweiz Swiss German: Schwyz or Schwiiz Suisse Svizzera Svizra officially the Swiss Confederation The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom, the UK or Britain,is a Sovereign state located The United States of America —commonly referred to as the A Skype user anywhere 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 and Norway, forbid the registration of their telephone numbers to anyone without a physical presence or citizenship in the country. This article is about the country For a topic outline on this subject see List of basic France topics. Norway ( Norwegian: Norge ( Bokmål) or Noreg ( Nynorsk) officially the Kingdom of Norway, is a Constitutional

Videoconferencing

Videoconferencing was introduced in January 2006 for the Windows and Mac OS X platform clients. A videoconference (also known as a videoteleconference) is a set of interactive Telecommunication technologies which allow two or more locations to interact Microsoft Windows is a series of Software Operating systems and Graphical user interfaces produced by Microsoft. Mac OS X (mæk oʊ ɛs tɛn is a line of computer Operating systems developed marketed and sold by Apple Inc, the latest of which is pre-loaded on all currently Skype 2. 0 for Linux, which was released on March 13, 2008, also features support for videoconferencing. Linux (commonly pronounced ˈlɪnəks Events 1138 - Cardinal Gregorio Conti is elected Antipope as Victor IV, succeeding Anacletus II. 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common ^[4]

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 that of mid-range videoconferencing systems. ^[5]

Skype on mobile devices

On April 24, 2008, Skype announced that they offer Skype on around 50 mobile phones. ^[6] On October 29, 2007, Skype launched its own mobile phone under the brand name 3 Skypephone, which runs a BREW OS. BREW ( Binary Runtime Environment for Wireless) is an application development platform created by Qualcomm for mobile phones. ^[7]

Skype is available for the N800 and N810 Internet Tablets. The Nokia N800 Internet Tablet is a wireless Internet appliance from Nokia, originally announced at the Las Vegas CES 2007 Summit The Nokia N810 Internet Tablet is an Internet appliance from Nokia, announced on October 17 2007 at the Web 2

Skype is available for the PSP (PlayStation Portable) Slim and Lite when you download the 3. 90 firmware update, but you need a microphone that connects to the PSP 2000 headphones. ^[8]

Skype is available on mobile devices running Windows Mobile. Windows Mobile is a compact Operating system combined with a suite of basic applications for Mobile devices based on the Microsoft Win32 ^[9] The official Symbian version is currently under development. Symbian OS is an open Operating system, designed for Mobile devices with associated libraries, User interface frameworks and ^[10] Official Skype support is available on Symbian and Java as part of X-Series together with mobile operator 3. X-Series from 3 is a mobile broadband offering from 3. It is priced like fixed line broadband.

Other companies produce dedicated Skype phones which connect via WiFi. Wi-Fi (ˈwaɪfaɪ is the trade name for the popular wireless technology used Third party developers, such as Nimbuzz and Fring, have allowed Skype to run in parallel with several other competing VoIP/IM networks in any Symbian or Java environment. Nimbuzz is a MoIP ( Mobile VoIP) application compatible with virtually all Mobile phones with Internet Connectivity. fring is an israeli 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 Nimbuzz have made Skype available to BlackBerry users. The BlackBerry is a Wireless Handheld device introduced in 1999 as a two-way pager

Security features

Main article: Skype security

Secure communication is a feature of Skype; encryption cannot be disabled, and is invisible to the user. Skype is a Voip system developed by Skype Technologies SA and owned by EBay. Secure communication includes means by which people can share information with varying degrees of certainty that third parties cannot know what was said Skype reportedly uses non-proprietary, widely trusted encryption techniques: RSA for key negotiation and the Advanced Encryption Standard to encrypt conversations. In Cryptography, RSA is an Algorithm for Public-key cryptography. In Cryptography, the Advanced Encryption Standard ( AES) also known as Rijndael, is a Block cipher adopted as an Encryption ^[11] 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 trivially easy, of course, for anybody to set up an account using any name; the displayed caller's name is no guarantee of authenticity.

One major problem with Skype is that its source code is not open source, and therefore cannot be inspected by most people - including most security specialists - for back doors that can be exploited by hackers or government agents. In Computer science, source code (commonly just source or code) is any sequence of statements or declarations written in some Human-readable Open source is a development methodology which offers practical accessibility to a product's source (goods and knowledge A backdoor in a Computer system (or Cryptosystem or Algorithm) is a method of bypassing normal Authentication, securing remote access to a computer Security specialist Bruce Schneier said in one of his monthly Crypto-Gram newsletters,^[12] that "In the cryptography world, we consider open source necessary for good security; we have for decades. Bruce Schneier (born 15 January 1963) is an American Cryptographer, Computer security specialist and Writer. " ^[13]

Issues

Security concerns

A third party paper analyzing the security and methodology of Skype was presented at Black Hat Europe 2006. ^[14] It analyzed Skype and made these observations:

• Skype keeps chatting on the network, even when idle (even for non-supernodes. May be used for NAT traversal)
• Assumes a 'blind trust' of anything else speaking Skype
• Ability to build a parallel Skype network
• Lack of privacy (Skype has the keys to decrypt calls or sessions)
• 'Heap overflow' in Skype
• Skype makes it hard to enforce a (corporate) security policy
• No way to know if there is or will be a 'backdoor'
• Skype has been found to access BIOS data^[15] to identify individual computers and provide DRM protection for plug-ins. NAT traversal is a general term for techniques to establish and maintain TCP/IP network connections which traverse Network address translation (NAT gateways A backdoor in a Computer system (or Cryptosystem or Algorithm) is a method of bypassing normal Authentication, securing remote access to a computer Digital rights management ( DRM) is a generic term that refers to Access control technologies used by hardware manufacturers publishers and Copyright holders ^[16][17]
• There is no assurance that Skype calls are not being intercepted.
• Skype is owned by eBay, whose privacy policy is perhaps the least protective of customers of any large corporation. eBay Inc is an American Internet company that manages eBaycom an Online auction and shopping Website in which people and businesses buy and eBay claims it goes above and beyond what it is required to do by law, seeking out and giving police all the information it stores about users excluding some financial data, for which they require a subpoena. A subpoena (səˈpiːnə is commonly defined as a written command to a person to Testify before a Court or be punished ^[18]

Skype service issues

• There have been complaints about Skype's poor customer support. ^[19] As of June 2007, Skype did not provide a way to contact customer support, offering indirect assistance through its web portal only. There have also been criticisms of Skype blocking and disabling customer accounts from using the SkypeOut service. ^[20]
• While available for Windows, Mac OS X and Linux (i386 platform) operating systems, there is no Skype version for the Palm OS, used in mobile devices like the Treo 700p smartphone. Microsoft Windows is a series of Software Operating systems and Graphical user interfaces produced by Microsoft. Mac OS X (mæk oʊ ɛs tɛn is a line of computer Operating systems developed marketed and sold by Apple Inc, the latest of which is pre-loaded on all currently Linux (commonly pronounced ˈlɪnəks Palm OS (also known as Garnet OS) is an embedded Operating system initially developed by U The Palm Treo 700p is a cell phone with advanced capabilities commonly referred to as a Smartphone.
• Skype has been criticized for bugs and delays in its Linux version. ^[21]
• Users of Skype on Mac OS X report poor audio quality when connecting to Mac/Mobile clients, with newer audio engines showing more and more problems. Mac OS X (mæk oʊ ɛs tɛn is a line of computer Operating systems developed marketed and sold by Apple Inc, the latest of which is pre-loaded on all currently Audio quality when connecting from Mac to Windows seem to be acceptable.
• Skype cannot be used with VOIP analogue telephone adapters (ATAs). Consequently, Skype users are limited to either using software phones or expensive Skype only hardware. However, there are applications that enable Skype users to connect to SIP providers. ^[22]
• SkypeOut has been criticized because it does not support caller ID in the United States, where people frequently reject calls from unrecognized numbers. For the protein involved in the synthesis of Major histocompatibility complex II see CLIP (protein. ^[23] The recipient sees "+0000123456" instead of a real phone number. By contrast, the Gizmo service shows the user's call-in number on caller ID. Gizmo5 (formerly known as Gizmo Project) is the name of a Peer-to-peer VoIP network and of a proprietary Freeware ^[24] On June 6, 2008, Skype extended its outgoing caller ID support to include USA online numbers, as well as verified cellular numbers from various countries. ^[25]
• SkypeOut does not support storing or (automatically) calling numbers with extensions. ^[26] Instead, a user must call the number (without the extension), wait for the call to connect and then manually enter the extension. This means that many business customers in practice need a separate contact list that includes extensions, causing the built-in contact list to be of little use. This is by many customers considered a fairly basic feature, and other phone services typically support it by allowing numbers to contain a symbol to represent a pause, as in "1-800-123-4567 x54321" or "1-800-123-4567,,,54321" where 54321 is the extension.

Compliance with the Communications Assistance for Law Enforcement Act

In May 2006, the FCC successfully applied the Communications Assistance for Law Enforcement Act to allow wiretapping on digital phone networks. The Communications Assistance for Law Enforcement Act ( CALEA) is a United States Wiretapping law passed in 1994 (Pub Wiretap redirects here For the radio program see WireTap (radio program Telephone tapping (or wire tapping / wiretapping in Skype is not yet compliant with the act, and has so far stated that it does not plan to comply. ^[27]

Censorship in China

Skype is one of many companies (others include AOL, Google, Microsoft, Yahoo, Cisco) which has cooperated with the Chinese government in implementing a system of Internet censorship in the People's Republic of China. Google Inc is an American public corporation, earning revenue from advertising related to its Internet search, e-mail, online Microsoft Corporation is an American multinational Computer technology Corporation, which rose to dominate the Home computer Niklas Zennström, chief executive to Skype, told reporters that its joint venture partner in China is operating in compliance with domestic law. "TOM Online had implemented a text filter, which is what everyone else in that market is doing," said Zennström. TOM Online ( HKGEM: 8282 is a private mobile Internet company in China, operating the popular Chinese-language Internet portal (www "Those are the regulations," he said. "I may like or not like the laws and regulations to operate businesses in the UK or Germany or the US, but if I do business there I choose to comply with those laws and regulations. I can try to lobby to change them, but I need to comply with them. China in that way is not different. "^[28]

Since late September, users in China trying to download the Skype software are redirected to the TOM site from which a modified Chinese version can be downloaded. Activists in China are warning about the possibility that TOM's versions have or will have more trojan capability. This article refers to a form of Malware in computing terminology ^[29]

Company timeline of events

2002

• September 2002: investment from Draper Investment Company. September 2002: January - February - March - April - May - June - July - August -

2003

• April 2003: Skype. April 2003: January - February - March - April - May - June - July - August - September com and Skype. net domain names registered.
• August 2003: First public beta version released. August 2003: January - February - March - April - May - June - July - August -

2005

• September 2005: SkypeOut banned in South China. PortalCurrent events News collections and sources WikipediaNews collections and sources. Skype (skaɪp is Software that allows users to make telephone calls over the Internet. ^[30]
• October 2005: eBay purchased Skype (Oct 14). PortalCurrent events News collections and sources See WikipediaNews collections and sources. eBay Inc is an American Internet company that manages eBaycom an Online auction and shopping Website in which people and businesses buy and ^[31]
• December 2005: videotelephony introduced. PortalCurrent events News collections and sources See WikipediaNews collections and sources. A videophone, also known by the trademarked name Picturephone, is a Telephone which is capable of both audio and Video Duplex transmission ^[32]

2006

• April 2006: Number of registered users reaches 100 million. Stories without links will be removed'. News stories must be in English
• October 2006: Skype 2. October 2006 was a month that began on a Sunday The month was marked by a nuclear test by North Korea that prompted that passing of Resolution 1718 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. ^[33] Skype 3. 0 for Windows is released. ^[34]

2007

• March 2007: Skype 3. March 2007 is the third month of the year It began on a Thursday, and ended 31 days later on a Saturday. 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. August 2007 is the eighth month of that year It began on a Wednesday and 31 days later ended on a Friday. 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. Events 778 - The Battle of Roncevaux Pass, at which Roland is killed Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. 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. Events 1384 - The Hongwu Emperor of Ming China, Emperor Dong hears a case of a couple who tore paper money bills while fighting Events 986 - A Byzantine army was destroyed in the pass of Trajan's Gate by the Bulgarians under the Comitopuli Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. ^[35][36] 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 ^[37]
• November 2007: Skype users are set to lose their 020 7 numbers after 20 December 2007. Events in November All Saints' Day (formerly All Hallows Day a Christian holy day is celebrated on November 1, the day after Halloween Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 69 - Vespasian, formerly a general under Nero, enters Rome to claim the title of Emperor. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. ^[38]

2008

• January 30, 2008: Skype released for the Sony PSP hand-held gaming system. Events 1648 - Eighty Years' War: The Treaty of Münster is signed ending the conflict between the Netherlands and Spain 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common is a multinational conglomerate corporation headquartered in Minato Tokyo, Japan, and one of the world's largest Media conglomerates with
• March 13, 2008: Skype 2. Events 1138 - Cardinal Gregorio Conti is elected Antipope as Victor IV, succeeding Anacletus II. 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common 0 for Linux released with support for videoconferencing.

Usage and traffic

Date	Total user accounts (in millions)[39][40][41]	Skype to Skype minutes (in billions)	Skype Out minutes (in billions)	Net revenue USD (in millions)
Q4 2005	74. 7	N/A	N/A	N/A
Q1 2006	94. 6	6. 9	0. 7	35
Q2 2006	113. 1	7. 1	0. 8	44
Q3 2006	135. 9	6. 6	1. 1	50
Q4 2006	171. 2	7. 6	1. 5	66
Q1 2007	195. 5	7. 7	1. 3	79
Q2 2007	219. 6	7. 1	1. 3	90
Q3 2007	245. 7	6. 1	1. 4	98
Q4 2007	276. 3	N/A	N/A	115
Q1 2008	309. 3	14. 2	1. 7	126

As of December 31, 2007 Skype had 276 million user accounts. Events 406 – Vandals, Alans and Suebians cross the Rhine, beginning an invasion of Gallia. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Users may have more than one account, and it is not possible to identify users with multiple accounts.

It was reported that 12,547,006 concurrent Skype users were online as of April 16, 2008. Events 1178 BC - A Solar eclipse may have marked the return of Odysseus, legendary King of Ithaca, to his kingdom 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common ^[42]

Date	Users [43]	Days
2008-02-18	12,000,000	42
2008-01-07	11,000,000	84
2007-10-15	10,000,000	259
2007-01-29	9,000,000	82
2006-11-08	8,000,000	71
2006-08-29	7,000,000	155
2006-03-27	6,000,000	66
2006-01-20	5,000,000	92
2005-10-20	4,000,000	155
2005-05-18	3,000,000	93
2005-02-14	2,000,000	117
2004-10-20	1,000,000	418
2003-08-29	0	-

The volume of international traffic routed via Skype is significant, though small compared to total global switched and VoIP traffic. 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common Events 3102 BC - Epoch (origin of the Kali Yuga. 1229 - The Sixth Crusade: Frederick II Holy 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common Events 1325 - Alfonso IV becomes King of Portugal. 1558 - France takes Calais, the last continental Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 533 - Byzantine General Belisarius makes his formal entry into Carthage, having conquered it from the Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 904 - Sergius III comes out of retirement to take over the papacy from the deposed Antipope Christopher. Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. Events 1519 - Hernán Cortés enters Tenochtitlán and Aztec ruler Moctezuma welcomes him with great a Celebration Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. Events 708 - Copper coins are minted in Japan for the first time (Traditional Japanese date: August 10, 708) Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. Events 196 BC - Ptolemy V ascends to the throne of Egypt. 1309 - Pope Clement V excommunicates Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. Events 250 - Emperor Decius begins a widespread persecution of Christians in Rome. Year 2005 ( MMV) was a Common year starting on Saturday (link displays full calendar of the Gregorian calendar. Events 1740 - Maria Theresa takes the throne of Austria. France, Prussia, Bavaria and Saxony Year 2005 ( MMV) was a Common year starting on Saturday (link displays full calendar of the Gregorian calendar. Events 1152 - Henry II of England marries Eleanor of Aquitaine. Year 2005 ( MMV) was a Common year starting on Saturday (link displays full calendar of the Gregorian calendar. Events 842 - Charles the Bald and Louis the German swear the Oaths of Strasbourg in the French and German "MMIV" redirects here For the Modest Mouse album see " Baron von Bullshit Rides Again " Events 1740 - Maria Theresa takes the throne of Austria. France, Prussia, Bavaria and Saxony Year 2003 ( MMIII) was a Common year starting on Wednesday of the Gregorian calendar. Events 708 - Copper coins are minted in Japan for the first time (Traditional Japanese date: August 10, 708) 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. ^[44]

Skype incorporates some features which tend to hide its traffic, but it is not specifically designed to thwart traffic analysis and therefore does not provide anonymous communication. Traffic analysis is the process of intercepting and examining messages in order to deduce information from patterns in Communication. An anonymous P2P computer network is a particular type of Peer-to-peer network in which the users are anonymous or pseudonymous by default Some researchers have been able to watermark the traffic so that it is identifiable even after passing through an anonymizing network^[45]. Digital watermarking is the process of embedding information into a digital signal Tor ( The Onion Router) is a Free software implementation of second-generation Onion routing – a system enabling its users to communicate anonymously

System and software

Versions now exist for Microsoft Windows (2000, XP, Vista and Windows Mobile), Mac OS X (Intel and PPC) and Linux (32-bit x86 only). Microsoft Windows is a series of Software Operating systems and Graphical user interfaces produced by Microsoft. Windows 2000 (also referred to as Win2K) is a preemptive, interruptible graphical and business-oriented Operating system designed to work with Windows XP is a family of 32-bit and 64-bit Operating systems produced by Microsoft for use on Personal computers including home and Windows Vista (ˈvɪstə is a line of Operating systems developed by Microsoft for use on Personal computers including home and business desktops Windows Mobile is a compact Operating system combined with a suite of basic applications for Mobile devices based on the Microsoft Win32 Mac OS X (mæk oʊ ɛs tɛn is a line of computer Operating systems developed marketed and sold by Apple Inc, the latest of which is pre-loaded on all currently Linux (commonly pronounced ˈlɪnəks Under Windows Skype can be run from a USB stick without being installed on the target computer. ^[46] The Linux version runs on FreeBSD through its Linux binary compatibility layer. FreeBSD is a Unix-like free Operating system descended from AT&T UNIX via the Berkeley Software Distribution (BSD branch through Skype can also run in Solaris branded zones. Solaris is a Unix -based Operating system introduced by Sun Microsystems in 1992 as the successor to SunOS. Solaris Containers (including Solaris Zones) is an implementation of Operating system-level virtualization technology first made available in 2005 as part of

Detailed changelogs

• Detailed Windows changelog
• Detailed Mac changelog
• Detailed Linux changelog

Skype protocol

Main article: Skype Protocol

Skype uses a proprietary Internet telephony (VoIP) network. Skype uses a Proprietary Internet telephony ( VoIP) network The protocol has not been made publicly available by Skype and official applications using the protocol The word proprietary indicates that a party or proprietor exercises private Ownership, control or use over an item of Property. Voice-over-Internet protocol ( VoIP, vɔɪp is a protocol optimized for the transmission of voice through the Internet The protocol has not been made publicly available by Skype and official applications using the protocol are proprietary and closed-source. Proprietary software is Computer software on which the producer has set restrictions on use private modification copying, or republishing. Proprietary software is Computer software on which the producer has set restrictions on use private modification copying, or republishing. The main difference between Skype and standard VoIP clients is that Skype operates on a peer-to-peer model rather than the more usual client-server model. For other uses of the term see Peer-to-peer (disambiguation For peer-to-peer networks used for file sharing see File sharing The client-server Software architecture model distinguishes client systems from server systems which communicate over a Computer network The Skype user directory is entirely decentralized and distributed among the nodes of the network—i. A node ( Latin nodus, ‘knot’ is a critical element of any Computer network. e. , users' computers—which allows the network to scale very easily to large sizes (currently about 240 million users)^[47] without a complex centralized infrastructure costly to the Skype Group.

See also

• Presence information
• Comparison of VoIP software
• Mobile VoIP
• Comparison of instant messaging clients
• Comparison of instant messaging protocols
• Secure communication

References

External links

• Official Skype website
• Scientific Research on Skype (Reverse Engineering, etc.)
• An Experimental Study of the Skype Peer-to-Peer VoIP System
• Skype Security Evaluation by Tom Berson (Anagram Laboratories)
• VoIP and Skype security by Simson L. Garfinkel (Tactical Technology Collective)
• Skype security, obfuscation and protection against reverse-engineering techniques analyzed at Black Hat conference 2006

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