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Voice over IP
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ECE 499VoIP2 Introduction Basics of VoIP Comparisons with current phone systems VoIP Protocols VoIP Issues Telephone Regulation Future of VoIP VoIP and OSU
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ECE 499VoIP3 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.
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ECE 499VoIP4 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.
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ECE 499VoIP5 VoIP Basic Technology Voice over IP (VoIP) is the process of sending an audio signal (usually voice) over a network using internet protocol.
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ECE 499VoIP6 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.
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ECE 499VoIP7 Comparison Example An important difference between the IP phones and current phone services is the amount of redundant data sent. Jack Jill Jack Jill Hi How are You? Great!!! Current Phone Implementation IP Phones
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ECE 499VoIP8 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
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ECE 499VoIP9 H.323 For use where there is no guranteed QoS 2 Phases –Call Setup –Capability Exchange
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ECE 499VoIP10 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)
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ECE 499VoIP11 SIP Example 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 SIP Client Caller Proxy Server 1 Redirect Server Proxy Server 2 Location Server Location Server SIP Client Callee Proxy Server 3 1 2 3 4 5 6 7 8 9 10 11 12 13 14
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ECE 499VoIP12 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
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ECE 499VoIP13 Current Implementations IP Phone –Soft –Hard Analog Telephone Adapter Line Gate Way Private Branch Exchange (PBX) Video Games, IM
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ECE 499VoIP14 IP Phone
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ECE 499VoIP15 ATA
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ECE 499VoIP16 Line Gate Way
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ECE 499VoIP17 PBX
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ECE 499VoIP18 Security Concerns Include… 1) Privacy 2) Ensure correct billing 3) Protection from Denial of Service (DoS) 4) Protection from packet manipulation.
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ECE 499VoIP19 Security
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ECE 499VoIP20 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.
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ECE 499VoIP21 VoIP – Minimum requirements Broadband connection Attitude to try something new Other requirements depend on VoIP implementation
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ECE 499VoIP22 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
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ECE 499VoIP23 VoIP vs. PSTN Carrier Lines Bandwidth Added Features Expandability and Upgradeability Typical Cost of a Business Line Rental Typical Local Call Cost Free Calls
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ECE 499VoIP24 VoIP Issues Reliability –QoS –PoE Security Phone Regulations
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ECE 499VoIP25 Quality of Service Improvement for any time-dependent internet application
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ECE 499VoIP26 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
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ECE 499VoIP27 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
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ECE 499VoIP28 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
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ECE 499VoIP29 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.
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ECE 499VoIP30 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
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ECE 499VoIP31 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
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ECE 499VoIP32 OSU Phone Lines Telephone wiring being routed
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ECE 499VoIP33 OSU Phone Connections Wiring to the outside Telephone connections to Patch Panel
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ECE 499VoIP34 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
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ECE 499VoIP35 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
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ECE 499VoIP36 How do I get VoIP ??!! Service Providers like Vonage Soft IP phones Santa Claus??
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ECE 499VoIP37 Demonstration Using Skype: www.skype.com Download software Install Call
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ECE 499VoIP38 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
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