A teleconference is the live exchange and mass communication of information among several persons and machines remote from one another but linked by a telecommunications system. Terms as audio conferencing, telephone conferencing and phone conferencing are also sometimes used to refer to teleconferencing. The telecommunications system may support the teleconference by providing one or more of the following audio, video, and/or data services by one or more means, such as telephone, computer, telegraph, teletype, radio, and television. Internet teleconferencing includes internet telephone conferencing, videoconferencing, and Augmented Reality conferencing. Internet telephony involves conducting a teleconference over the Internet or a Wide Area Network. One key technology in this area is Voice over Internet Protocol (VOIP). Popular software for personal use includes Skype, Google Talk, Windows Live Messenger and Yahoo Messenger.
In the past few years, corporations have gotten bigger and more spread out. Many American employees -- more than 44 million in 2004 -- also do at least some of their work from home [ref]. Since offices and employees can be thousands of miles apart, getting everyone into the same room for meetings and training has become decidedly impractical for a lot of companies.
That's why teleconferencing -- the real-time exchange of information between people who are not in the same physical space -- has become such a big industry. The American audio conferencing industry alone reported $2.25 billion in revenue in 2004 [ref]. Through teleconferencing, companies can conduct meetings, customer briefs, training, demonstrations and workshops by phone or online instead of in person.
Conference calls let groups of people -- from a few to hundreds -- communicate by phone. Banks and brokerages often use conference calls to give status reports to large numbers of listeners. Other businesses use conference calls to help coworkers communicate, plan and brainstorm. To connect to the call, attendees call a designated number (MeetMe conferencing), or an operator or moderator calls each participant (ad hoc conferencing).
Conference calls connect people through a conference bridge, which is essentially a server that acts like a telephone and can answer multiple calls simultaneously. Software plays a large role in the bridge's capabilities beyond simply connecting multiple callers.
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A company can have its own bridge or can contract with a service provider for conference call hosting. Providers frequently offer add-on features for conference calls, such as:
Attendee polling
Call recording
In-call operators or attendants
Companies using Voice over IP (VoIP) telephones can also host conference calls themselves if the VoIP software supports them.
Many phone conferencing systems require a login and personal identification number (PIN) to access the system. This helps protect confidential and proprietary information during the call.
Video phones can add a visual element to conference calls, but businesses often need to share other visual information.
Skype
Skype (pronounced /ˈskaɪp/) 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 phones can be made for a fee. Additional features include instant messaging, file transfer and video conferencing.
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, Colombia, Denmark, the Dominican Republic, Estonia, Finland,France, Germany, Hong Kong, Hungary, Ireland, Italy, Japan, Mexico, New Zealand, Poland, Romania, South Korea, Sweden,Switzerland, the Netherlands, the United Kingdom, and the United States. 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 and Germany, 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 Windows and Mac OS X platform clients. Skype 2.0 for Linux, 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.
The word "Skypecasting" is a portmanteau of "Skype" and "broadcasting". Its original usage referred to recording Skype voice over IP voice calls and teleconferences. The recordings would be used as podcasts, which allow audio or video content to be syndicated over the Internet. Skype launched a "Skypecasts Beta" service in 2006 where it remained in beta until its end in September 2008. Skypecasts hosted public conference calls, up to 100 people at a time. Unlike ordinary Skype p2p conference calls, Skypecasts support 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 Act, Skype is not an "interconnected VoIP provider". As a result, the U.S. National Emergency Number Association recommends that all VoIP users have an analog line available as a backup.
System and software
Skype uses a proprietary Internet telephony (VoIP) network, called the Skype protocol. 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-peer model (originally based on the Kazaa software), rather than the more usual client-server model. The Skype user directory is entirely decentralized and distributed among the nodes 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 SIP-based VoIP networks.
Many networking and security companies who 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.729 and SVOPC. Skype added a Skype-created codec called SILK to Skype for Windows 4 and other Skype clients. SILK is intended to be "lightweight and embeddable".
Skype security is a secure communication; encryption cannot be disabled, and is invisible to the user. Skype reportedly uses non-proprietary, widely trusted encryption techniques: RSA for key negotiation and the Advanced Encryption Standard 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 Linux, Linux-based Maemo, Mac OS X (Intel and PPC), iPhone OS (iPhone and iPod Touch), Microsoft Windows(2000, XP, Vista, Windows Mobile), and even Sony's PSP.
Complaints:
There have been complaints about Skype's poor customer support. As of April 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.
Google Talk
GTalk is a free Windows and web-based application for instant messaging and voice over internet protocol (VOIP), offered by Google Inc. The first beta version of the program was released on August 24, 2005.
Instant messaging between the Google Talk servers and its clients uses an open protocol, XMPP, allowing users of other XMPP clients to communicate with Google Talk users. VoIP in Google Talk is based around the Jingle protocol. The technology used within the Google server network however is not publicly known.
The Google Talk client is only available for Microsoft Windows (2000, XP, Server 2003,Vista and Windows 7). Mobile clients are also available for the BlackBerry, iPhoneand T-Mobile G1. With the release of the Google Talk gadget, users of all platforms supported by Adobe Flash Player can also use Google Talk.[1] Many other XMPP clients are compatible with Google Talk, and support a variety of other platforms.
Google Talk (along with other networks such as Yahoo! Messenger, Windows Live Messenger and AOL Instant Messenger) is often used as a conduit or "vector" for delivering malicious software such as spyware, viruses, worms, and trojans to unsuspecting computer users. The two methods used by malicious users to deliver malware over the IM vector are (1) sending a file transfer with a virus-infected file, (2) delivering a message with socially engineered content containing a web address (URL) containing active malicious code.
Google has announced that a major goal of the Google Talk service is interoperability. Google Talk uses XMPP to provide real-time extensible messaging and presence events, including offline messaging and voice mailing. On January 17, 2006, Google enabled server-to-server communications, federating itself with any Jabber server that supports the dialback protocol
The most common method of delivering a malicious payload is the use of social engineering to construct a message that appears to be coming from a contact on the recipient's contact list. A socially engineered message is one that is written in a friendly, informal manner, that could easily be mistaken as coming from a friend. The message usually will say something like "Click here to see pics of me from vacation!" or "Is this you?" with a web address—known as a "poison URL" -- for the recipient to click. Upon clicking the web address, the recipient is connected to a website containing active content, which is immediately downloaded to the recipient's computer. In most cases, the payload contains an installer, a number of hidden files containing text, and code which causes the same socially engineered message with poison URL to be sent to every contact on the contact list. When the message is sent to all contacts, the cycle starts again, as each contact believes they are receiving a message from a trusted friend. In this manner, IM-borne malware is capable of propagating very rapidly through company and external networks.
Complaints
During Google Talk's ongoing beta period, users have voiced concerns about the service. There has been some discussion on theGoogle Talk Help group concerning the fact that certain personal information is made publicly available without any method to control it. This allows anyone who has a Google Talk member on their buddy list to see when the user is and is not active on their computer, for example, by observing the user's idle status as provided by the Google Talk client. Certain third-party software products have been developed to provide more control over the information made available.
gAlwaysIdle, for example, allows users to be 'always idle' or 'never idle', thus preventing personal presence information from being fed to the Google Talk service. Alternative client software, such as Pidgin, Adium, and Trillian also permit more privacy controls than the official Google Talk client. As of October 5, 2008, the official client allows blocking a user (thus also suspending status notifications to that user) but nothing more granular is apparent.
Future releases
Google reports that they are working on adding new features such as supporting SIP in a future release, which would broaden the userbase for the program.
A screenshot showing the Google Talk, Labs Edition preview release
Additionally as part of Google's and eBay's Multi-Year Agreement on August 28, 2006, it was announced that the companies will look into making Google Talk users able to communicate with Skype: "The companies will also explore interoperability between Skype and Google Talk via open standards to enable text chat and online presence."
A screen shot was posted on May 18, 2007 as part of the Google Apps presentation, showing some phone integration in Google Talk. A Google engineer confirmed they have been using it internally for some time on March 2, 2008.
Clues from one of the first Google Chrome December 2008 revisions suggests that a new Talk client is in the works
Yahoo! Messenger
Yahoo! Messenger is an advertisement-supported instant messaging client and associated protocol provided by Yahoo!. Yahoo! Messenger is provided free of charge and can be downloaded and used with a generic "Yahoo! ID" which also allows access to other Yahoo! services, such as Yahoo! Mail, where users can be automatically notified when they receive new email. Yahoo! also offers PC-PC, PC-Phone and Phone-to-PC service, file transfers, webcam hosting, text messaging service, and chat rooms in various categories.
Yahoo! Messenger was originally launched under the name Yahoo! Pager on March 9, 1998.
In addition to instant messaging features similar to those offered by ICQ, it also offers (on Microsoft Windows) features such as: IMVironments (customizing the look of Instant Message windows, some of which include authorized themes of famous cartoons such as Garfield or Dilbert), address-book integration and Custom Status Messages. It was also the first major IM client to feature BUZZing and music-status. Another recently added feature is customized avatars.
Webcam
Yahoo’s software now allows users with the most current updated versions (messenger 8 through 9) to utilize its webcam service. This option enables users from distances all over the world to view others who have installed a webcam on their end. The service is free with provided speeds averaging from a range in between 1 to 2 frames per second. The resolution of the images can be seen starting at 320 x 240 pixels or 160 x 120.
On October 13, 2005, Yahoo! and Microsoft announced plans to introduce interoperability between their two messengers, creating the second-largest real-time communications service userbase worldwide: 40 percent of all users (AIM currently holds 56 percent). The announcement comes after years of third-party interoperability success (most notably, Trillian, Pidgin) and criticisms that the major real-time communications services were locking their networks. Microsoft has also had talks with AOL in an attempt to introduce further interoperability, but so far, AOL seems unwilling to participate.
Interoperability between Yahoo! and Windows Live Messenger was launched July 12, 2006. This allows Yahoo! and Windows Live Messenger users to chat to each other without the need to create an account on the other service, provided both contacts use the latest versions of the clients. For now, it's impossible to talk using the voice service among both messengers.
Complaints:
Yahoo! Messenger users are subject to unsolicited messages (SPIM) and the problem remains unresolved. Blogs and websites addressing this issue are supportive of the chat environment, and writers genuinely want to continue using the service, yet express frustration about Yahoo's apparent failure to address spam and other related problems. User queries are met with forms and replies that Yahoo is "working to resolve the problem," yet there is no evident progress. As of 2007 it is estimated that at least 60% of all users who use Yahoo chat rooms are bots. Yahoo has introduced a CAPTCHA system to help filter out bots from joining chat rooms but it has done little to actually stop the problem and has only inconvenienced human users.
Yahoo! released a preview version of Yahoo! Messenger: Yahoo! Messenger for Windows Vista. It has been designed to exploit the new design elements of Vista's Windows Presentation Foundation and entitled a whole new user interface and features. It lacked some basic functions such as webcam support and Chat. It has been discontinued.
The Mac OS X client version 3.0 Beta 3 has been released: file transfers have been re-enabled as have group conferences.
A screenshot of Yahoo! Messenger 3.0b1 for Mac OS X
§ Windows - 10.0.0.525
§ Mac OS X - 3.0 Beta 4 (build 178870) - February 10, 2009
§ Several third-party clients exist that can connect to the Yahoo! Messenger network, such as Adium and the now-discontinued Fire and Proteus. Adium can access the chat rooms, while the others cannot.
§ Unix - 1.0.4 / September 2003. It can still be downloaded from Softpedia.
§ Version 1.0.6 can be downloaded from the Unix Beta page:http://public.yahoo.com/~mmk/
§ A compatible version for Linux is available - Gyachi
Windows Live Messenger
Windows Live Messenger (formerly named MSN Messenger, and colloquially referred to as simply MSN) is an instant messaging client created by Microsoftthat is currently designed to work with Windows XP, Windows Vista, Windows 7,Windows Server 2003, Windows Server 2008, and Windows Mobile. The client has been part of Microsoft's Windows Live set of online services since 2005. It connects to Microsoft's .NET Messenger Service. The client was first released as MSN Messenger on July 22, 1999, and as Windows Live Messenger on December 13, 2005. The service attracts over 330 million active users each month.
In addition to its basic functionality and general capability as an instant messaging client, Windows Live Messenger offers the following features:
Sharing folders
The Sharing Folder feature is an alternative to the "direct transfer" method of file distribution. When a user wants to deliver a file to another person on his or hercontact list, the "sharing folder" window appears, which is an individualized representation of all previously shared items.
When files are added to the "sharing folder" for that particular person, the file will automatically be transferred to the corresponding computer when they are online. This means that the folder is literally "shared" between two computers. If a user deletes a file, for example, the file will also be deleted from the corresponding computer's shared folder.
To minimize risk of virus-infected transfers, the "sharing folder" feature is bundled with an anti-virus program. The "sharing folder" feature can only be used on computers with NTFS-formatted hard disks.
The Sharing Folder feature has been discontinued in the latest version of Windows Live Messenger (2009), and replaced with access to Windows Live SkyDrive instead.
PC-to-phone calls
In addition to PC-to-PC calls that have been supported in previous versions, Windows Live Messenger now supports PC-to-phone calls with Windows Live Call. In the US, this feature is supported by Verizon, branded as "Verizon Web Calling". Orange France also has a similar service. This feature is only available in selected countries, including the US, the UK, France, Germany, the Netherlands, Austria, Ireland, Finland, Belgium, Spain, and Italy. Verizon ended service in August 2008 and was replaced in the US with Telefonica, while Orange will offer the service for the rest of the world.
Interoperability
On October 13, 2005, Yahoo! and Microsoft announced plans to introduce interoperability between their two messengers, creating the second largest instant messaging user base worldwide: 40 percent of all users. The announcement came after years of third-party interoperability success (most notably, Trillian, Pidgin) and criticisms from Google that the major real time communications services were locking their networks. Interoperability between Yahoo! and Windows Live Messenger was launched July 12, 2006. This allows Yahoo! and Windows Live Messenger users to chat to each other without the need to create an account on the other service, provided both contacts use the latest versions of the clients. However, if a user uses an older or third-party client, they will appear offline to the users on the other network.
Security vulnerability
On September 12, 2007, the Windows Live Messenger blog posted a fix that resolved a security problem. It reported of a security vulnerability in versions of Messenger older than 8.1, that the released fix would resolve. This led to an auto-update being released to all older versions. Versions running on Windows 2000 and below were required to update to a new version of MSN Messenger 7.0, and versions running on Windows XP and above were required to update to Windows Live Messenger 8.1
On August 27, 2009, the Windows Live Messenger blog posted that due to a security problem, all users of versions 8.1 and newer need to update to the latest version, 14.0.8089. The mandatory upgrade requirement will be fully phased in by late October 2009.
Windows Live Messenger uses the Microsoft Notification Protocol (MSNP) over TCP (and optionally over HTTP to deal with proxies) to connect to the .NET Messenger Service—a service offered on port 1863 of "messenger.hotmail.com." The current version is 15 (MSNP15), used by Windows Live Messenger and other third-party clients. MSNP15 introduces a different authentication mechanism.
The protocol is not completely secret; Microsoft disclosed version 2 (MSNP2) to developers in 1999 in an Internet Draft, but never released versions 8 or higher to the public. The .NET Messenger Service servers currently only accept protocol versions from 8 and higher, so the syntax of new commands sent from versions 8 and higher is only known by using packet sniffers like Wireshark.
Why is it useful?
Teleconferencing reaches large or sparsely-populated areas. It offers opportunities for people in outlying regions to participate. People participate either from home or from a local teleconferencing center. In Alaska, where winter weather and long distances between municipal cities serve as roadblocks to public meetings, the State legislature has developed the Legislative Telecommunication Network (LTN). As an audio teleconference system, LTN can receive legislative testimony from residents or hold meetings with constituents during "electronic office hours." Although its main center is in the capitol building, it has 28 full-time conference centers and 26 voluntary conference centers in homes or offices of people who store and operate equipment for other local people. The system averages three teleconferences per day when the legislature is in session.
Teleconferencing provides broader access to public meetings, as well as widening the reach of public involvement. It gives additional opportunities for participants to relate to agency staff and to each other while discussing issues and concerns from physically separate locations. It enables people in many different locations to receive information first-hand and simultaneously
A wider group of participants means a broader range of ideas and points of view. Audio interaction makes dialogue more lively, personal, and interesting. Teleconferencing provides an immediate response to concerns or issues. It enables people with disabilities, parents with childcare conflicts, the elderly, and others to participate without having to travel.
Teleconferencing saves an agency time and travel costs. Without leaving their home office, staff members can have effective meetings that reach several people who might not otherwise be able to come together. Teleconferencing reduces the need for holding several meetings in different geographic areas, thereby decreasing public involvement costs, particularly staff time and travel. Teleconferencing often enables senior officials to interact with local residents when such an opportunity would not exist otherwise, due to distance and schedule concerns.
Teleconferencing saves people money. It saves travel time, transportation cost, babysitter fees, and lost work time. New York City’s Minerva Apartment Towers set up a closed-circuit teleconference transmission between two apartment buildings for residents to discuss issues within their site. Residents wishing to speak went to a room in their own building to make comments over a link-up between the apartment buildings.
Teleconferencing saves time by reaching more people with fewer meetings. A teleconference may reach more people in one session than in several sessions held in the field over several weeks. Usually, it is difficult to schedule more than two or three public meetings in the field within one week, due to staff commitments and other considerations. However, teleconference connections to several remote locations save several days or weeks of agency time and facilitate a fast-track schedule.
What are the costs?
Teleconferencing costs vary, depending on the application. The costs of installing a two-way telephone network are modest. For complex installations, including television, radio, or satellite connections, costs are significantly higher. Hiring outside help to coordinate equipment purchases or design an event adds to the expense.
For modest teleconferencing efforts, equipment and facilities are the principal costs. Higher costs are associated with higher performance levels of equipment, more transmission facilities, or more locations. Agencies may be able to rent a facility or set one up in-house. The San Diego Association of Governments is building its own central teleconferencing facility to provide increased opportunities for the agency to use this technique.
It is possible to share teleconferencing costs among organizations. Many States have teleconferencing capabilities in State colleges. States may have non-profit organizations with teleconferencing capabilities. Outside resources include cable television stations or donated use of private company facilities. Agency staff time devoted to the event may be a significant expense.
What are the drawbacks?
Teleconferences are somewhat formal events that need prior planning for maximum usefulness. Although they require pre-planning and careful timing, teleconferences are conducted informally to encourage participation and the exchange of ideas.
A large number of people is difficult to manage in a single teleconference, with individuals attempting to interact and present their points of view. One-on-one dialogue with a few people is usually preferable. Widely divergent topics are also difficult to handle with a large number of people participating in a teleconference.
Costs can be high. Costs are incurred in equipment, varying sites for connections, transmission, and moderator training. Substantial agency staff time to coordinate and lead is likely.
Teleconferences take time to organize. Establishing technical links, identifying sites and constituencies, and coordinating meetings can be time-consuming. Materials need to be prepared and disseminated. However, teleconferencing saves time by being more efficient than in-person meetings, and the savings may offset staff efforts and other costs.
Staffing needs can be significant. Personnel such as technicians and agency staff to set up and coordinate meetings are required. Training to conduct a conference is necessary. However, staff time and resources may be significantly less than if personnel have to travel to several meetings at distant locations.
Community people are alienated if a meeting is poorly implemented or if anticipated goals are not met. People need to be assured that the project and planning staff is mindful of their concerns. Technical and management difficulties, such as poor coordination between speakers or people being misunderstood or not heard, result in bad feelings.
Teleconferencing reduces opportunities for face-to-face contact between participants and proponents of plans or projects. It cannot replace a desirable contact at individual meetings between stakeholders and agency staff in local sites. Effective public involvement includes meetings in the community to obtain a feel for the local population and issues. (See Public Meetings/Hearings; Non-traditional Meeting Places and Events.) A teleconference supplements rather than replaces direct contact with local residents and neighborhoods. Video conferencing, by contrast, enhances opportunities for face-to-face exchange. The goals of a teleconference must be clear and manageable to avoid a potential perception of wasted time or frivolous expenditures.
When is it used most effectively?
Teleconferencing is effective when participants have difficulty attending a meeting. This occurs when people are widely dispersed geographically and cannot readily meet with agency staff. Teleconferencing also serves people with disabilities, the elderly, and others who may have difficulties with mobility. Teleconferencing is effective when it focuses on specific action items that deserve comment. Teleconferences aid in prioritizing issues and discussing immediate action items. Detailed, wide-ranging discussions may be more properly handled with written materials and in-person interaction. Teleconferencing helps give all participants an equal footing in planning and project development. Teleconferences overcome geographic dispersal and weather problems to aid contact with agency staff.
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