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Voice over IP

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  1. Voice over IP Carrie Kolstad, Marc Orr, Nick Patron ECE 499 School of Electrical Engineering and Computer Science Oregon State University

  2. Introduction • Basics of VoIP • Comparisons with current phone systems • VoIP Protocols • VoIP Issues • Telephone Regulation • Future of VoIP • VoIP and OSU VoIP

  3. How Phones Used To Work (pre - 1960) • Phones were connected by a direct physical line from 1 user to another user. • The line remained open for the entire duration of the call. • A call from California to New York required a large length of copper wire connecting the 2 talkers. It would cost a lot for the call because the talkers would actually own a 3,000 mile long copper wire for the period of time they were on the phone. VoIP

  4. How phones work now • Your voice is digitized and sent along with other users across a fiber optic cable. • These calls are transmitted at a fixed rate of 64 kilobits per second (Kbps) in each direction, for a total transmission rate of 128 Kbps. So in a 10-minute conversation, the total transmission is 9,600 KB. • If you look at a typical phone transmission much of the transmitted data is wasted. While you are talking the other party is listening (and vice versa) such that only half the line is used at any time. VoIP

  5. VoIP Basic Technology • Voice over IP (VoIP) is the process of sending an audio signal (usually voice) over a network using internet protocol. VoIP

  6. How IP Phones Work • IP Phones receive phone numbers then determine if the number is an IP “soft phone” or a physical “hard phone” by contacting the VoIP company’s Call processor. • If it a soft phone then an IP address is acquired, otherwise the call will go through the VoIP company’s phone network. • IP phones data is sent as packets and only when there is data to be sent i.e. talking. VoIP

  7. Comparison Example Current Phone Implementation IP Phones Jill Hi Hi Jill Jack Jack How are You? How are You? Great!!! Great!!! • An important difference between the IP phones and current phone services is the amount of redundant data sent. VoIP

  8. Network Protocol Structure for Internet Telephony H.323 or SIP RTP, RTCP, RSVP, RTSP Transport Layer (UDP, TCP) Network Layer (IP, IP Multicast) Data Link Layer Physical Layer VoIP

  9. H.323 • For use where there is no guranteed QoS • 2 Phases • Call Setup • Capability Exchange VoIP

  10. Session Initialization Protocol • Application layer In charge of establishing and terminating sessions in Internet telephony • Client's Methods • Invite - invites callee(s) to participate in a call • ACK - Acknowledges the invitation • Options - Inquires about media capabilities without setting up a call • Cancel - Terminates the invitation • Bye - Terminates a Call • Register - Sends users Location to a registrar (a SIP server) VoIP

  11. SIP Example Location Server SIP Client Caller • 1. Caller Sends INVITE john@home.or • 2. Proxy Uses DNS and sends request • 3- 4. john@home.or Isn't logged on request sent to location server john@work.or located • 5. return john@work.or to proxy server • 6. attempt next proxy server • 7- 8. consults location server to discover John's local address john_doe@my.work.or • 9- 10. Proxy 3 forwards the invitation to the callee • 11-14. John accepts the call and returns acknowledgment to caller 3 4 1 Redirect Server 2 14 Proxy Server 1 5 6 Location Server 7 13 Proxy Server 2 8 9 12 Proxy Server 3 11 SIP Client Callee 10 VoIP

  12. Functionality of IP Phones • They come with all the regular phone options including: • Caller ID • Call waiting • Call transfer • Repeat dial • Return call • Three-way calling • As well as Call Forwarding that can be altered via the internet VoIP

  13. Current Implementations • IP Phone • Soft • Hard • Analog Telephone Adapter • Line Gate Way • Private Branch Exchange (PBX) • Video Games, IM VoIP

  14. IP Phone VoIP

  15. ATA VoIP

  16. Line Gate Way VoIP

  17. PBX VoIP

  18. Security Concerns Include… 1)Privacy 2)Ensure correct billing 3)Protection from Denial of Service (DoS) 4) Protection from packet manipulation. VoIP

  19. Security VoIP

  20. Ensure Secure VoIP 1) Encrypt VoIP traffic 2) Properly configure firewalls. 3) Consider segmenting voice and data traffic by using a virtual LAN. 4) Use proxy servers in front of corporate firewalls to process incoming and outgoing voice data. 5) Make sure that server based IP PBXs are locked down and protected against viruses and DoS attacks. VoIP

  21. VoIP – Minimum requirements • Broadband connection • Attitude to try something new • Other requirements depend on VoIP implementation VoIP

  22. Why VoIP ??? 1) Often times it is easier to install 2) Save Money 3) Easier to upgrade 4) Keep your voice and its pertinent data on the same lines 5) Different devices can communicate with each other VoIP

  23. VoIP vs. PSTN • Carrier Lines • Bandwidth • Added Features • Expandability and Upgradeability • Typical Cost of a Business Line Rental • Typical Local Call Cost • Free Calls VoIP

  24. VoIP Issues • Reliability • QoS • PoE • Security • Phone Regulations VoIP

  25. Quality of Service • Improvement for any time-dependent internet application VoIP

  26. Power over Ethernet • Useful application in the deployment of VoIP phones • Power over Ethernet (PoE) allows devices to be powered by the ethernet connection • Advantages • Allows use in remote areas • Can connect to a network backed up by a UPS so when power outages occur, phone is still powered and functional VoIP

  27. VoIP and Telephone Regulations • VoIP telephone service is a direct competitor with the traditional phone service. • This new use for the Internet is unregulated by the government and is deemed a “internet service” rather than a “voice service”. • If left unregulated, traditional phone companies may loose hundreds of millions of dollars VoIP

  28. VoIP Regulation • $$$ is not the only force behind regulating VoIP • Regulation would bring standards of service including, but not limited to 911 availability • As of May 19, 2005, the FCC has required that all VoIP providers deliver all 911 calls to the customer’s local emergency operator. • Customers must be able to update their local information at any time, even remotely. • Applicable to any phone that connect to the PSTN VoIP

  29. Future Application: Cell phones • Cell phones may soon have the ability to function over both current cell networks as well as wireless (802.11x) using VoIP • Early versions of Wi-Fi VoIP phones are already in Japan • Current versions work as “either – or” phones • Many obstacles before seamless switching between networks can happen. VoIP

  30. OSU and VoIP • Toured the OSU data and telephone network facility • Jon Dolan, Assoc. Director of Network Services at OSU, discussed his views on the future with VoIP and OSU Marc Orr, Carrie Kolstad, and Nick Patron in the basement of Kerr Administration VoIP

  31. OSU Phone Network • New Telephone Switch installed in the early 90’s – cost OSU $8 million • Currently supports over 12,000 phones across campus and outlying areas OSU Telephone Switch VoIP

  32. OSU Phone Lines Telephone wiring being routed VoIP

  33. OSU Phone Connections Wiring to the outside Telephone connections to Patch Panel VoIP

  34. OSU and VoIP now • Currently deploys about 40 IP phones to remote sites • Cascades Campus • New Nanotechnology Lab at HP-Corvallis • No plans to implement IP phones on Corvallis campus at this time VoIP

  35. OSU and VoIP in the Future • Three main requirements for phones • Reliability • Function • Cost • Reasons for not switching to IP Phones • Not as reliable • Phone Network = wire • Data Network = data switches, higher probability of failure • QoS vs. Bigger Pipe • No extra functionality • Not cost effective • IP phones must still go through the Telephone Switch • Current system is adequate VoIP

  36. How do I get VoIP ??!! • Service Providers like Vonage • Soft IP phones • Santa Claus?? VoIP

  37. Demonstration • Using Skype: www.skype.com • Download software • Install • Call VoIP

  38. Summary • Basics of VoIP • Current Telephones vs. IP Phones • VoIP Protocols • VoIP Issues • Regulation of VoIP • Cell phones and VoIP • Future of VoIP and OSU VoIP

  39. Questions??