TELEPHONY FUNDAMENTALS

VoIP Telephony Basics

Voice over Internet Protocol (VoIP) is a technology that allows voice data to be digitized and split into packets for sending over an Internet protocol (IP) network. Because a user's voice is turned into digital packets, the quality of a VoIP telephone call is higher than that of a regular phone call placed on a packet-switched telephone network (PSTN) system.

Using VoIP standards, companies have created telephony systems that offer high-level features for end users. These high-level services include: call forwarding, call hunting, and simultaneous ringing.

VoIP 911 Issues

Because a VoIP device can be moved to any location that has a high-speed Internet connection, a few problems exist. The most talked about problem is the lack of full 911 support. This problem arises because the protocol used for VoIP does not transmit a caller's physical location. To combat this problem, some service providers set up an emergency services system. This type of system allows emergency calls to be routed to non-emergency call centers.

This issue should be resolved in the very near future. To correct it, VoIP companies are working with the major telephone companies to gain access to their 911 emergency infrastructure. Until these changes are made, VoIP providers have been telling customers to update their 911 address information regularly.

Though some problems still exist with VoIP, customers are increasingly signing up for the service. Users are interested in saving money and are willing to look past a few shortcomings to do this. With increasing popularity and improving call quality, VoIP services are gaining traction and are expected to rapidly increase in the coming years.

How VoIP Works

VoIP is a reinvention of an already working system, and is set to revolutionize how the world's phone system operates.

The way VoIP works is an analog signal (user's voice) is turned into digital data and split into packets. These packets are then routed to another phone via the Internet. At the termination point, the packets are reassembled in the correct order.

The transmission speed of packets is increased by using CODECs. The CODEC used depends on the VoIP service provider. CODECs that provide better voice quality result in larger files. Thus, there are more packets to send over the Internet and more bandwidth is required.

The Workings of a VoIP Phone System

Data networks, unlike circuit networks, don't maintain a constant connection between two points for the transfer of data. Instead, they try to retrieve data only as it is needed. As well, data networks transfer data packets over many different paths. The term used for this is packet switching.

Because data networks send data only when it is needed, they tend to work efficiently. A few steps are involved in the transmission of information across a data network.

• The sending device takes an analog signal, digitizes it, and then chops the file into packets. Each packet contains an address and information about how it should be reassembled.
• Inside each packet is a payload. The payload contains a piece of the digital file.
• The sending device takes the packet and forwards it to a router. That router forwards it to a router that is closer to the receiver. This continues on until the packet reaches its destination.
• When the packets finally reach their destination they are reassembled into the original file using the information contained in them.

VoIP Requirements

There are a few VoIP requirements that must be met before you can start using a VoIP service.

To use a VoIP service you will need to have a broadband Internet connection, telephone, and an ATA device

Broadband Internet Connection

VoIP requires a high-speed Internet connection. Depending on the VoIP provider, an analog telephone adapter (ATA) can require as much as 80Kbps of speed on the upload side.

Dialup connections are not suitable for VoIP for a few reasons. First, the connection is not fast enough to produce a clear telephone call. Second, because they are turned on and off, the phone, too, would always be turned on and off. It is quite obvious why this is bad. Lastly, you would need phone service with a local carrier so that your modem could dial out.

m could dial out.

Telephone

Almost any telephone will work with VoIP. However, because most VoIP service providers don't support "lighting up the house," expandable telephones are often recommended. With an expandable base phone, the main phone and base need to be plugged into a phone jack. The others simply need to be plugged into an electrical outlet. This makes it possible to put phones throughout a house when using an ATA with only one active phone jack.

If you do not use an expandable base phone, you have a few other options. One option is to use just one phone for your entire house. The other option is to use a splitter on the ATA device and run several telephone lines from it

ATA

An ATA is a device that converts an analog telephone into an IP telephone. An ATA may , often times, be referred to as a VoIP Gateway or a TA. No matter the term used to describe them, ATAs all work in a similar manner.

ATAs convert an analog signal (voice) into a digital signal. This conversion is done using different CODECs.

JOSE LEONARDO MONCADA TORRES 

C.I 18878408

CRF

http://www.voip-resource.com

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