Voice Over Internet Protocol

1. Voice Over Internet Protocol By Eric Rice

2. History • First telephone was patented in 1870 • Rotary dialing first done in 1891 • 1905-Party Line • 1910-5.1 million customers • 1941-Attacks on Pearl Harbor cause a 100-400 percent spike in long distance nation wide

3. History cont. • 1949-the average calls placed in a day reach 180 million. • 1975-there are 140 million telephone lines in the US and AT&T controls 85% of them • 1993-AT&T offers Caller ID • 1995-Vocal Tec release first VOIP software • 1996-First cable modem service offered by Roger Communications • 2001-Vonage founded • March 2002-Vonage initiates service

4. The Issues • Reliability • 911 service availability • Voice Quality • Delay • Jitter • Features • Signaling Protocol

5. Reliability • The current standard • Five-nines (5 min of downtime a year) • “Networks go down all the time” • High Internet Traffic

6. 911 Availability • Currently address information is linked to a number • Due to VoIP portability, locations are not defined • In order to receive 911 service it must first be set up • Mobile phones have this same problem • Alternate solutions include developing new port mapping technologies • Using GPS to locate callers

7. Voice Quality • Goals • Make it comparable to wire line • Minimize bandwidth • Wire line Voice codec is G.711 • 64kbps • MOS 4.3 (mean opinion score) • VoIP Voice codec G.729 • 8kbps • MOS 4.0 What?

8. Other Codecs • These codecs use a number of different compression algorithms to minimize required bandwidth

9. Delay • Delay is measured using Round Trip Time • Keep delay less then 300ms • If greater then 300ms may seem like making an international call: take this situation

10. Jitter • Occurs when delay changes • If the delay increases and decreases sporadically it makes conversations sound choppy • RTP (Real Time Transport Protocol) • Adds a sequence number and a time stamp to UDP packets • This allows for delay and jitter to be calculated accurately

11. Solutions to Jitter and Delay • Add bandwidth to the entire Internet • We find ways to use up all the bandwidth we are given • Reserve bandwidth on the routers it uses • This would not be fair to the rest of the packets • Temporary solution is to simply route the calls through the current switch network.

12. SIP (Session Initiation Protocol) • Very simple protocol to use • Allows for advanced features to be applied by the user without a subscription

13. Features • Cheaper Service • No long distance charges • Caller ID • Call Forwarding • Call Screening • Users can do other things than just block a call • If Kitrek were to call, I would be able to forward his call to an insult hotline

14. Features • Voicemail • Check it online with fast-forward, rewind, and pause • Check it through email • Check it over the phone • Require unknown callers to provide an intent for calling • If a telemarketer calls they would have to tell what they wanted • It would then be displayed on the caller ID

15. Conclusion • VoIP is a technology which will eventually replace the current Switch network. • With new and fully customizable features, along with cheaper service and no long distance charges. We can expect to see VoIP much more in the future.

16. Resources • [1] Danial Collins. (2001). Carrier Grade Voice Over IP. New York. McGraw-Hill. • [2] John Shepler. (2005). The Holy Grail of five-nines reliability. • Retrieved April 1, 2005 from http://searchnetworking.techtarget.com/generic/0,295582,sid7_gci1064318,00.html • [3] Tim Lorello, Rich Tehrani (2005). E-9-1-1. Internet Telephony, 8, (3), 40-41. • [4] FCC. (2004) VoIP: FCC Consumer Facts. Retrieved April 1, 2005 from http://www.fcc.gov/cgb/consumerfacts/voip.pdf • [5] Vonage. (2005) Features. Retrieved April 1, 2005 from • http://www.vonage.com/features.php