How VoIP Works. VoIP, or Voice over Internet Protocol , is a method for taking analog audio signals and turning them into digital data that can be transmitted over the Internet. How is this useful? - PowerPoint PPT Presentation
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Midpeninsula IBM PC Club 2006-07-17 How VoIP Works VoIP, or Voice over Internet Protocol, is a method for taking analog audio signals and turning them into digital data that can be transmitted over the Internet. How is this useful? VoIP uses a standard Internet connection to place phone calls. By using some of the free VoIP software that is available to make Internet phone calls, you are bypassing the phone company (and its charges) entirely. From: http://electronics.howstuffworks.com/ip-
Transcript
Midpeninsula IBM PC Club 2006-07-17
How VoIP Works
VoIP, or Voice over Internet Protocol, is a method for taking analog audio signals and turning them into digital data that can be transmitted over the Internet.
How is this useful?
VoIP uses a standard Internet connection to place phone calls. By using some of the free VoIP software that is available to make Internet phone calls, you are bypassing the phone company (and its charges) entirely.
The Standard Phone System vs. The VoIP System – i.e. Circuit vs. Packet Switching
Circuit Switching Existing phone systems are driven by a very reliable but somewhat inefficient method for connecting calls called circuit switching. Circuit switching is a very basic concept that has been used by telephone networks for more than 100 years. When a call is made between two parties, the connection is maintained for the duration of the call. Because you are connecting two points in both directions, the connection is called a circuit. This is the foundation of the Public Switched Telephone Network (PSTN).
Midpeninsula IBM PC Club 2006-07-17
IP Telephony – Circuit Switching
Midpeninsula IBM PC Club 2006-07-17
The Standard Phone System vs. The VoIP System – i.e. Circuit vs. Packet Switching
Packet SwitchingData networks do not use circuit switching. Your Internet connection would be a lot slower if it maintained a constant connection to the Web Page you were viewing at any given time.
Instead, data networks simply send and retrieve data as you need it. And, instead of routing the data over a dedicated line, the data packets flow through a chaotic network along thousands of possible paths. This is called packet switching.
Midpeninsula IBM PC Club 2006-07-17
IP Telephony – Packet Switching
Midpeninsula IBM PC Club 2006-07-17
“Flavors” of VoIP service
● ATA – analog telephone adaptor – or analog-to-digital converter
Connects a standard phone to your computer or your Internet connection Providers: e.g. Vonage and AT&T CallVantage
● IP Phones – Specialized phones with an RJ-45 Ethernet connector IP phones connect directly to your router and have the hardware and
software necessary to handle the IP call. Soon, Wi-Fi IP phones will be available make VoIP calls from any Wi-Fi hot
spot.
● Computer-to-computer – All you need is the software, a microphone, speakers, a sound card and an
Internet connection,
Midpeninsula IBM PC Club 2006-07-17
VoIP Products Tested
● Skype – with
PC to PC D-Link Linksys “Cordless Internet Telephone Kit”
Midpeninsula IBM PC Club 2006-07-17
Skype
What is Skype? Skype is a little piece of software that lets you make free
calls to anyone else on Skype, anywhere in the world.
Also, until the end of 2006, you can make free calls to landlines and mobiles in the US and Canada from Skype.
If you and your friends, family or business contacts are using webcams, you can also make free video calls.
You can even call landlines and mobile phones at really cheap per minute rates (and there’s no setup or subscription fee).
Midpeninsula IBM PC Club 2006-07-17
Skype
Skype works on most kinds of computers Windows Mac OS X Linux Pocket PCs.
Supports calls, chats and file transfers
Prerequisites:
Software, microphone, speakers, sound card and an Internet connection
Midpeninsula IBM PC Club 2006-07-17
Skype
Make (international) calls with Skype that are really cheap.
Free Calls!
• within the USA till Dec 31st 2006
• to the UK July 15-16th
• to Mexico July 22-23rd
• to Japan July 29-30th
SkypeOut
Midpeninsula IBM PC Club 2006-07-17
Skype
SkypeIn: ● Get your own phone number for Skype. Family,
friends and business contacts can call you from traditional phones, and you pick up the call in Skype.
Skype Voicemail: ● If you’re offline in Skype, too busy or just plain
don't feel like talking to anyone right now, let Skype Voicemail pick up the call instead.
Midpeninsula IBM PC Club 2006-07-17
DPH-50U > Skype™ USB Phone Adapter
Product Features: Receive/make both regular telephone and
Skype calls on the same phone In-call switching, conference calling, call
forwarding, and toll bypassing Use Skype™ to talk to other Skype users
anywhere in the world.
Midpeninsula IBM PC Club 2006-07-17
Dlink DPH-50U Diagram
Midpeninsula IBM PC Club 2006-07-17
Midpeninsula IBM PC Club 2006-07-17
Linksys Cordless Internet Telephony Kit - CIT200
Skype with Handset Convenience! You don't have to sit in front of your computer to talk to your
friends with Skype™ USB Base Station connects to your PC and puts your Skype contact list on the handset's
screen -- just choose and talk Handset features illuminated
Caller ID screen, speakerphone and call waiting Also supports SkypeOut
dialing™ incoming SkypeIn™ calls and Skype VoiceMail
Midpeninsula IBM PC Club 2006-07-17
VoIP Products Summaryhttp://electronics.howstuffworks.com/ip-telephony.htm
Skype PC to PC D-Link Linksys “Cordless Internet Telephone Kit”
Note: The Forrester Research Group predicts that nearly 5 million U.S. households will have VoIP phone service by the end of 2006.
Perhaps the biggest draws to VoIP for the home users that are making the switch are price and flexibility.
