W3: Internet Protocol (IP) Telephony

Research the key words "IP telephony" or "telephony". Then complete the following: 

1. Get the references of 3 sites that come up with the best, most informative results.
   
2. Based on your scanning of these 3 sites,
   
3. Summarize a one paragraph description of what IP Telephony means
   
4. Provide which source you used exactly where in your paragraph, by providing the article author's last name, year of the publication of the article or the last modified date of the website, and the page or paragraph number where your citation can be found. Use the following format (authorLastName, year, p.# or para.#).
   
5. List 3 examples of services that use IP Telephony, with a short description of each service