Topic: Voice over IP

external image Microsoft-vrea-Voice-over-IP-2.jpg

Description: VoIP for short, it is a category of hardware and software that allows people to talk through the internet using IP rather than traditional PSTN (Public Switched Telephone Network) circuit transmissions. It is as if they were using a phone, except people do not have to pay a surcharge in order to use VoIP if they talk to another with the same VoIP program; the internet service is the only cost to the consumer. This is very practical in the business world, where the employees must communicate quickly and easily. VoIP copanies help tremendously to cut costs by providing this free service. A sample architecture is provided below:



external image voip2.gif



Applications: Skype, CoolTalk, NetMeeting

Terminology: IP: specifies the format of packets, also called datagrams, and the addressing scheme.

Switch: In networks, a device that filters and forwards packets between LAN segments

PSTN: the international telephone system based on copper wires carrying analog voice data

Internet: A global network containing millions of computers

Router: A device that forwards data packets along networks

Circuit: A set of electronic components that perform a particular function in an electronic system

Citations/References: TechWeb: Circuit, Webopedia: Router, Webopedia: Internet, Webopedia: PSTN, Webopedia: IP, Webopedia: VoIP, Phone Picture 1, VoIP Architecture

Related Links:
www.fcc.gov/voip/
en.wikipedia.org/wiki/Voice_over_IP
www.voip-info.org
www.vonage.com ,
http://www.skype.com/