What is VOIP? Meaning & Voice Over IP Technology

VOIP is an acronym for Voice Over Internet Protocol, or in more common terms phone service over the Internet.
If you have a reasonable quality Internet connection you can get phone service delivered through your Internet connection instead of from your local phone company.

Some people use VOIP in addition to their traditional phone service, since VOIP service providers usually offer lower rates than traditional phone companies, but sometimes doesn’t offer 911 service, phone directory listings, 411 service, or other common phone services. While many VoIP providers offer these services, consistent industry-wide means of offering these are still developing.

How does VOIP work?

A way is required to turn analog phone signals into digital signals that can be sent over the Internet.
This function can either be included into the phone itself (See: VOIP Phones) or in a separate box like an ATA .

VOIP Using an ATA: Ordinary Phone —- ATA —- Ethernet —- Router —- Internet —- VOIP Service Provider
VOIP using an IP Phone: IP Phone —– Ethernet —– Router —- Internet —- VOIP Service Provider

It is also possible to bypass a VOIP Service Provider and directly connect to another VOIP user. However, if the VOIP devices are behind NAT routers, there may be problems with this approach.

VOIP connecting directly: IP Phone —– Ethernet —– Router —- Internet —- Router —- Ethernet —- IP Phone

Applications using VOIP

Traditional telephony applications, such as outbound call center applications and inbound IVR applications, normally can be run on VOIP.

There are a number of VoIP phone systems available on the market including, one example being 3CX which is a software-based VoIP PBX for Windows, Linux and the cloud. For a comprehensive list of solutions visit VoIP PBX and Servers.

Why use VOIP?

There are two major reasons to use VOIP

Lower Cost
Increased functionality

Lower Cost

In general phone service via VOIP costs less than equivalent service from traditional sources. This is largely a function of traditional phone services either being monopolies or government entities. There are also some cost savings due to using a single network to carry voice and data. This is especially true when users have existing under-utilized network capacity that they can use for VOIP without any additional costs.

In the most extreme case, users see VOIP phone calls (even international) as FREE. While there is a cost for their Internet service, using VOIP over this service may not involve any extra charges, so the users view the calls as free. There are a number of services that have sprung up to facilitate this type of “free” VOIP call. Examples are: Free World Dialup and Skype for a more complete list see: VOIP Service Providers

Increased Functionality

VOIP makes easy some things that are difficult to impossible with traditional phone networks.

Incoming phone calls are automatically routed to your VOIP phone where ever you plug it into the network. Take your VOIP phone with you on a trip, and anywhere you connect it to the Internet, you can receive your incoming calls.
Call center agents using VOIP phones can easily work from anywhere with a good Internet connection..

Books

If you use one of the Amazon links below to purchase a book voip-info.org will benefit.
This list is loosely in order starting with non-technical overviews and moving on to comprehensive technical references.

VOIP for Dummies, by Timothy V. Kelly

A non-technical introduction to VOIP

Switching to VOIP, by Ted Wallingford

An introduction that assumes some basic knowledge of computer networking

If you would like to recommend a VOIP book, please visit VOIP Books