Evidences Behind Skype Outage

Skype is one of the most successful VoIP application in the current Internet spectrum. One of the most peculiar characteristics of Skype is that it relies on a P2P infrastructure for the exchange of signaling information amongst active peers. During August 2007, an unexpected outage hit the Skype overlay, yielding to a service blackout that lasted for more than two days: this paper aims at throwing light to this event. Leveraging on the use of an accurate Skype classification engine, we carry on an experimental study of Skype signaling during the outage. In particular, we focus on the signaling traffic before, during and after the outage, in the attempt to quantify interesting properties of the event. While it is very difficult to gather clear insights concerning the root causes of the breakdown itself, the collected measurement allow nevertheless to quantify several interesting aspects of the outage: for instance, measurements show that the outage caused, on average, a 3-fold increase of signaling traffic and a 10-fold increase of number of contacted peers, topping to more than 11 million connections for the most active node in our network - which immediately gives the feeling of the extent of the phenomeno

Reasoning processes involved in ICT-mediated design communication

Conversational interaction is central to architectural design practice. New information and communication technologies (ICT) change the designer’s traditional way of communicating and interacting. In this paper we investigate how communication in the design process might be supported using ICT. With this aim, we study a text-based Skype conversation between a design teacher and a design student. We consider this conversation as part of an architectural design process and analyse it using linkography. From the linkograph analysis, specific features are identified that apply specifically to text-based Skype interactions. We conclude that online text-based Skype interaction can be one of the many possible interactions by means of communication media (sketching, conversation, modelling, and so forth) during the design process, and provides a distinct set of characteristics that might be considered by the designer

Skype

Skype, (skype.com) is a video, audio, and text-based communication tool that provides a platform where multiple users can engage in synchronous dialogue (Price & Wright, 2012). This software transforms a personal computer or mobile device into an Internet-based conferencing system with both recording and screen sharing capabilities (Yang, 2008)

Bursty egocentric network evolution in Skype

In this study we analyze the dynamics of the contact list evolution of millions of users of the Skype communication network. We find that egocentric networks evolve heterogeneously in time as events of edge additions and deletions of individuals are grouped in long bursty clusters, which are separated by long inactive periods. We classify users by their link creation dynamics and show that bursty peaks of contact additions are likely to appear shortly after user account creation. We also study possible relations between bursty contact addition activity and other user-initiated actions like free and paid service adoption events. We show that bursts of contact additions are associated with increases in activity and adoption - an observation that can inform the design of targeted marketing tactics.Comment: 7 pages, 6 figures. Social Network Analysis and Mining (2013

I Know Where You are and What You are Sharing: Exploiting P2P Communications to Invade Users' Privacy

In this paper, we show how to exploit real-time communication applications to determine the IP address of a targeted user. We focus our study on Skype, although other real-time communication applications may have similar privacy issues. We first design a scheme that calls an identified targeted user inconspicuously to find his IP address, which can be done even if he is behind a NAT. By calling the user periodically, we can then observe the mobility of the user. We show how to scale the scheme to observe the mobility patterns of tens of thousands of users. We also consider the linkability threat, in which the identified user is linked to his Internet usage. We illustrate this threat by combining Skype and BitTorrent to show that it is possible to determine the file-sharing usage of identified users. We devise a scheme based on the identification field of the IP datagrams to verify with high accuracy whether the identified user is participating in specific torrents. We conclude that any Internet user can leverage Skype, and potentially other real-time communication systems, to observe the mobility and file-sharing usage of tens of millions of identified users.Comment: This is the authors' version of the ACM/USENIX Internet Measurement Conference (IMC) 2011 pape

Should Australian courts give more witnesses the right to Skype?

Millions of people use Skype, a common form of social media that permitspeople to talk to each other over the internet. Courts in Australia havepermitted witnesses in at least a few instances to testify by Skype to date. Thisarticle examines whether Australian courts should permit witnesses to testifyby Skype more often. The article considers using videoconferencing, asopposed to Skype, and security issues associated with Skype. It alsoconsiders the impact that Skype may have upon considering witness credibility.Ultimately, it argues that Australian judicial officers may want to considerpermitting witnesses to testify by Skype if testifying by videoconference is notpossible, on a case by case basis. The authors believe that this is the firstscholarly article in Australia to focus on the issue of witnesses testifying bySkype

24% of Internet Users Have Made Phone Calls Online

Presents survey findings about trends in Americans' use of Skype, Vonage, and other Voice over Internet Protocol services to make phone calls by gender, age, race/ethnicity, income, education, and community type

An Analysis of the Skype Peer-to-Peer Internet Telephony Protocol

Skype is a peer-to-peer VoIP client developed by KaZaa in 2003. Skype claims that it can work almost seamlessly across NATs and firewalls and has better voice quality than the MSN and Yahoo IM applications. It encrypts calls end-to-end, and stores user information in a decentralized fashion. Skype also supports instant messaging and conferencing. This report analyzes key Skype functions such as login, NAT and firewall traversal, call establishment, media transfer, codecs, and conferencing under three different network setups. Analysis is performed by careful study of Skype network traffic