VOIP
 

What is VOIP:

Introduction:

VOIP is an acronym for Voice Over IP, 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.

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. VOIP is an acronym for Voice Over IP, 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.

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.

VOIP technologies available on GNU /LINUX:

Asterisk The open source PBX and multi-protocol VoIP server
sipX The SIP PBX for Linux from SIPfoundry
OpenPBX An open source PBX with support for OH323 PSTNGW
SIP Express Router (SER) The open source SIP proxy server
sipXphone sipXphone - The SIP softphone for Windows and Linux from SIPfoundry
sipXezPhone A new SIP softphone from SIPfoundry
GnomeMeeting The open source H.323 video softphone
Skype A proprietary protocol VOIP system built using Peer-to-peer (P2P) techniques.
Linphone The open source SIP softphone for Linux
KPhone KDE based Softphone for SIP protocol
PhoneGaim Gaim instant messaging client merged together with a Linux SIP softphone.
Twinkle QT sipphone