Requirements: PC running Windows 2000 or XP 400 MHz or faster processor 128 MB RAM 15 MB free disk space Sound Card, Speakers and Microphone or (preferably a headset with microphone). If your computer supports Bluetooth then your cell phone Bluetooth headset might be useful. Internet Connection (dial-up or broadband) As you are aware the Public Switched Telephone Network uses TDM (Time Division Multiplexing) for its network protocol. VoIP (Voice over Internet Protocol) uses IP for its network protocol. One day all telephony will use IP. Skype today uses IP packets to transmit voice over the Internet. This lab will demonstrate some characteristics along with the capability and voice quality of VoIP. Since Skype is continually improving its functionality and constantly improving its user interface, the install and documentation which follows may change over time. The following worked at the time of this publication. Download: Skype application from: http://www.skype.com/go/getskype Install when the option is presented to you Settings: accept all the default Configure: Use the wizard to setup your Skype account. If necessary Setup a proxy server, this may require your instructor assistance Execute the setup: accept all agreements You may elect to have Skype startup when you login, your choice depending on your school policy. Completed installation: you may launch Skype at any time using its icon on the Start Menu or the desktop. CAUTION: You will have an opportunity to enter person data. DO NOT enter any personal data about yourself since it will become available to millions of Skype users around the world. You should be aware that there are many predators who want your personal info to commit criminal acts. You must ask your classmates for their ids in order to set up a directory which is used to place calls. Place these ids in to your directory. Make a call to one of your class mates. After the conversation begins what do you notice about the sounds? there is a big delay Why do you think the sound is different on this Voice over IP conversation than on the public telephone network? Because the voice signals have to be changed from analog to digital, using a codec, and framed into packets before being sent over the network. And there is some delay as the packets travel over the network before reaching their destination and some packets will be lost along the way and perhaps surrogate packets are formed to replace those lost packets to smooth out the conversation. Go to the Internet and answer this question. What is “delay budget”. ______________________________________________________________________ What is the delay budget from source to destination? 150ms. What is the delay budget from source back to the source? 300ms. Why is delay budget important in Voice over Internet Protocol? To allow for delays caused by codecs, switch and router delays, other traffic on the network, security, and the building packets to replace lost packets. If the person talking with you over Skype were in another room would you notice the delay? NO What value does Skype hold for you? I have an opportunity to talk with anyone worldwide for free, if they have a computer, an Internet connection, and Skype. Your have just set up a Skype account that can be used any place in the world where you have access to the internet. Skype has a number of other communications features which you might be interested in Take some time and explore some of these features. Again be careful with disclosing your personal information on Skype or any other public access Internet applications. Additional features which may be of interest to you are: Skype-Out and Skype-In. For a small per minute cost you can call from your PC to a regular telephone using Skype-Out. Also Skype can provide you a phone number for your PC and for a small per minute cost anyone can call your computer from a Public Switched Telephone; home phone, cell phone, 802.11 phones, etc. Have Fun!