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Voice over Internet Protocol
(VoIP)
1. Terms and Definitions2. How Does it Work
• packet switching vs. circuit switching• what is needed by user• challenges
3. Benefits to small and medium sized Businesses
• convenience• pricing
4. Projections for the Future
Agenda
• DID Direct Inward Dial ( a phone number)• ITSP Internet Telephone Service Provider (Vonage, Binary Telecom)• PSTN - Public Switched Telephone Network• POTS - Plain Old Telephone Service (individual lines)• ILEC or LEC (Incumbent Local Exchange Carrier) Qwest/Verizon• CLEC (Competitive Local Exchange Carrier) Integra, XO• SIP (Session Initiation Protocol) Signaling that starts the communication process between
nodes; RTP (Real Time Protocol) to transmit the audio. • SIP Trunks - An Oxymoron because SIP allows multiple simultaneous calls on one DID.
Occasionally used to compare “lines” with T-1 Channels or POTS Lines. No more guessing at the right number of “outside lines” available.
• E911 – Enhanced 911 – provides a screen-pop at the Public Safety Access Point (PSAP) of caller’s location.
• QoS (Quality of Service) Routing priority for voice over other ordinary data on the networks. Newer routers from Cisco, Linksys and D-Link support QoS.
• G711 Codec– 64 kbps (plus overhead) per call. Same as POTS• G729 Codec – 8.5 kbps per call. Sound quality of a cell-phone.• LNP (Local Number Portability) One of the charges you pay each month for the privilege of
being able to move your number to another carrier.
Terms
(Wikipedia) A Protocol for the transmission of voice through the Internet or other packet switched networks, including your own Local Area Network (LAN) and Wide Area Network (WAN).
VoIP Definition
(Wikipedia) A fixed bandwidth circuit (or channel) between nodes so the users may communicate, as if the nodes were physically connected with an electrical circuit.
Circuit Switching
• Same routing system used by a computer to send and receive data (IP).
• Audio is divided into data-blocks (packets) – Each data packet has a header that identifies an IP
address to which it will go. – The route can be random; determined by speed, cost,
or peering among networks and service providers. – Packets arrive, are reassembled in the proper order.
• More efficient, allows more simultaneous calls to be made.
Packet Switching
• Efficiencies reflected in pricing. – Free if between Internet connections (Skype, other on-net calling). – $29.95 per month for a business line that includes all Centrex features,
compared with approximately $77 (plus LD) from Qwest/Verizon/AT&T.– Spreadsheet for comparing rates at: www.binarytelecom.com/costcompare.htm – Fewer taxes and surcharges.
• Convergence of networks.– Merging IT and Telephony departments. – No more costly service for Moves/Adds/and Changes.– More options for handsets.
• Online access to call detail 24x7. www.binarytelecom.com • Create a virtual office by using an additional number in another area code. It
rings into your main office and is a local call to your remote customers.• Cordless Wi-Fi enabled IP phones allow freedom of movement• Travelers can use a softphone on a laptop when out of the office.
Benefits
• Makes your PBX an outsourced Managed Service to an ITSP in a local tier-one data center. – supported with redundant fiber connections to the Internet,
generator back-up, and more network security
• Allows most of the features on an expensive PBX or Centrex service– Auto-attendant, voicemail, call transfers, music on hold.– Helps a small business create the impression it is a larger..
• No Licenses or depreciation• No Maintenance Agreements• More telephone options for expansion
Hosted PBX
• Any analog phone with the addition of an Analog Telephone Adapter (ATA) or Gateway device to connect an analog PBX
• Or IP phones made for VoIP
• Or IP enabled PBX
• Broadband Internet access
What is Needed
• Client-side ISP Services are the number one hurdle to successful VoIP experiences.– Inadequate upstream bandwidth
• Filtered, over-subscribed or without QoS.– Latency, Jitter & Packet Loss
• Frequent very brief interruptions (Jitter or Packet Loss), or calls that have a delay (Latency).
• Mean Opinion Score (MOS) Test at www.testyourvoip.com• E911 address updates essential.• Older fax machines don’t play nice with VoIP.
– ITSP needs T-38 Protocol.– Machine converts a digital image to analog and back to digital. Dropped
packets will interrupt transmission, and fail.– Keep a POTS line for faxes and emergencies. Strip it of all features to
keep costs down.
Challenges
– Market research firm In-Stat in 2006: Market for hosted VoIP services to grow 10-fold, to $1.27 billion by 2009, and by the end of this year, there will be approximately 3.9 million VoIP lines in the U.S. 2008 -16 million per TeleGeography Research.
– Since 2005, the RBOCs--AT&T, Verizon and Qwest--have lost over 17 million residential telephone lines to VoIP and Cell service
– Rapid Growth of IP PBXs• Asterisk – handles data packets very well.
– TrixBox and other manufacturers of IP PBXs now including this open source, Linux based, IP PBX (Linksys SPA 9000).
• Mitel, ShoreTel, NEC, Toshiba, GrandStream, Cisco, Allworx Adtran, Astra and AltiGen.
• Microsoft/Windows.– 3CX, MS Microsoft's OCS and Response Point phone system
for small businesses.
Future
• Voip will provide:– Lower Costs– More flexibility– More personal control
• Minimum need for new equipment
• Works great with any GOOD Internet access
Summary
• http://www.testyourvoip.com/ This is a valuable tool that will assist with evaluating a network for ample bandwidth.
• http://www.binarytelecom.com/costcompare.htm
Links