Tuesday, January 6, 2009
easy 1 2 3 guide for VOIP newbies
What is Voice over Internet Protocol (VoIP)?
Voice over Internet Protocol is a method of transmitting audio over the internet by encoding analog audio in a digital form, transmitting it over the internet, and decoding it back to analog form for listening. It is also known by the acronym "VoIP".
For some experties, it's an IP telephony term for a set of facilities used to manage the delivery of voice information over the Internet.VoIP involves sending voice information in digital form in discrete packets rather than by using the traditional circuit-committed protocols of the public switched telephone network (PSTN). A major advantage of VoIP and Internet telephony is that it avoids the tolls charged by ordinary telephone service.
WIKIPEDIA describes VoIP as a general term used for a family of transmission technologies for delivery of voice communications over the Internet or other packet-switched networks. Other terms frequently encountered and synonymous with VoIP are IP telephony and Internet telephony, as well as voice over broadband, broadband telephony, and broadband phone, when the network connectivity is available over broadband Internet access.
VoIP systems usually interface with the traditional public switched telephone network (PSTN) to allow for transparent phone communications worldwide.
VoIP can be a benefit for reducing communication and infrastructure costs by routing phone calls over existing data networks and avoiding duplicate network systems.
Isn't it amazing when we get to use this kind of opportunity; using the voice over internet protocol facility. All people in this world start talking bout VOIP. VOIP here and VOIP there.
Voice-over-IP systems carry telephony speech as digital audio, typically reduced in data rate using speech data compression techniques, packetized in small units of typically tens of milliseconds of speech, and encapsulated in a packet stream over IP.
VoIP derives from the VoIP Forum, an effort by major equipment providers, including Cisco, VocalTec, 3Com, and Netspeak to promote the use of ITU-T H.323, the standard for sending voice (audio) and video using IP on the public Internet and within an intranet. The Forum also promotes the user of directory service standards so that users can locate other users and the use of touch-tone signals for automatic call distribution and voice mail.
In addition to IP, VoIP uses the real-time protocol (RTP) to help ensure that packets get delivered in a timely way. Using public networks, it is currently difficult to guarantee Quality of Service (QoS). Better service is possible with private networks managed by an enterprise or by an Internet telephony service provider (ITSP).
A technique used by at least one equipment manufacturer, Adir Technologies (formerly Netspeak), to help ensure faster packet delivery is to use ping to contact all possible network gateway computers that have access to the public network and choose the fastest path before establishing a Transmission Control Protocol (TCP) sockets connection with the other end.
Using VoIP, an enterprise positions a "VoIP device" at a gateway. The gateway receives packetized voice transmissions from users within the company and then routes them to other parts of its intranet (local area or wide area network) or, using a T-carrier system or E-carrier interface, sends them over the public switched telephone network.
Benefits of VoIP
* More features and information available on the IP Telephones
* Concurrent support for legacy analog telephones and newer IP telephones
* Telecommuters now have a working corporate telephone extension at home
* Easier Extension and multi-site administration
* Unified corporate appearance over multiple locations
* Consolidated Infrastructure requirements resulting from the use of existing data networks
* Reduced long distance toll charges through Voice over IP trunking
Who should consider VoIP?
- Businesses with overseas contacts & partners
- Businesses with high call volumes
- International companies
Voice over Internet Protocol (VoIP)
Internet telephony refers to communication services, such as voice, facsimile, and voice-messaging applications, that are transported via the Internet, rather than the public switched telephone network (PSTN). So, Voice Over Internet Protocol (VoIP) allows you to make telephone calls using a computer network, over a data network like the Internet.
Uses of VoIP in your business...
Long-Distance Call Routing (VoIP to PSTN)- This service is ideal for businesses who use a great deal of internet access and are making a large number of phone calls.
Point-Point Connections (Voice IP to Voice IP calls)– This option works well for home workers, some types of small offices and remote users. By accessing the internet they are able to log in to the main office network and also run their telephones as extensions to the main office phone system.
VoIP Circuit Switching
Existing phone systems are driven by a very reliable but somewhat inefficient method for connecting calls called circuit switching.
Circuit switching is a very basic concept that has been used by telephone networks for more than 100 years. When a call is made between two parties, the connection is maintained for the duration of the call. Because you're connecting two points in both directions, the connection is called a circuit. This is the foundation of the Public Switched Telephone Network (PSTN).
Here's how a typical telephone call works:
1. You pick up the receiver and listen for a dial tone. This lets you know that you have a connection to the local office of your telephone carrier.
2. You dial the number of the party you wish to talk to.
3. The call is routed through the switch at your local carrier to the party you are calling.
4. A connection is made between your telephone and the other party's line using several interconnected switches along the way.
5. The phone at the other end rings, and someone answers the call.
6. The connection opens the circuit.
7. You talk for a period of time and then hang up the receiver.
8. When you hang up, the circuit is closed, freeing your line and all the lines in between.
Let's say you talk for 10 minutes. During this time, the circuit is continuously open between the two phones. In the early phone system, up until 1960 or so, every call had to have a dedicated wire stretching from one end of the call to the other for the duration of the call. So if you were in New York and you wanted to call Los Angeles, the switches between New York and Los Angeles would connect pieces of copper wire all the way across the United States. You would use all those pieces of wire just for your call for the full 10 minutes. You paid a lot for the call, because you actually owned a 3,000-mile-long copper wire for 10 minutes.
Telephone conversations over today's traditional phone network are somewhat more efficient and they cost a lot less. Your voice is digitized, and your voice along with thousands of others can be combined onto a single fiber optic cable for much of the journey (there's still a dedicated piece of copper wire going into your house, though). 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. Since there are 8 kilobits (Kb) in a kilobyte (KB), this translates to a transmission of 16 KB each second the circuit is open, and 960 KB every minute it's open. In a 10-minute conversation, the total transmission is 9,600 KB, which is roughly equal to 10 megabytes (check out How Bits and Bytes Work to learn about these conversions). If you look at a typical phone conversation, much of this transmitted data is wasted.
You may try it now. This is correct time for using the Voip - Voice Over Internet Protocol.
Labels: voip ipod telcom
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