A fast internet connection is vital if you have a business that is in need of fast communication.  If so, it is important to read up on T1 communications and look into T1 providers.  For IP networks, the reliable service of TCP is not appropriate for real-time applications because TCP uses retransmission to ensure reliability. The IP layer provides routing and network-level addressing; the data-link layer protocols control and direct the transmission of the information over the physical medium. The packets are then transmitted across the internet in compliance with a voice communications protocol or standard such as H.323, Media Gateway Control Protocol (MGCP), or Session Initiation Protocol.

If you purchase an IP packet with your VOIP system, when your IP packet (which contains your speech) arrives at the destination it must go through a similar process, but in reverse. As such the IP packets are disassembled to retrieve the compressed voice data, which can then be decompressed using the same codec that performed the compression. After the decompression, the original digital data is left which can then go through a digital to analog converter and be returned to its original analog voice format and be clearly heard and understood by your called party.

The digital bits must now be compressed into a standard format which can be transmitted faster and more efficiently. In VoIP, digital signal processors (DSPs) perform this compression using codecs which segment the voice signal into frames and store them in voice packets.

Communication networks are separate and serve a specific application, with the Internet serving data communications and the traditional PSTN (Public Switched Telephone Network) serving voice communications. Voice over Internet Protocol, or more commonly known as VoIP combines both voice and data communications on a single network. As such the Internet can be used as a means to deliver both forms of traffic. VoIP enables network equipment to carry and send voice and fax traffic over an IP network. The biggest advantage of this is that as you are no longer using the phone company's long distance lines, and you will be able to have long distance conversations for an unlimited length of time, with no additional charge.

The majority of phones utilize the G711 codec, but the G723 codec is emerging as the popular codec choice for IP Telephony applications. This codec is preferred due to its smaller size and higher compression which allows for easier transport over the internet.

The compressed data must then be encapsulated within IP packets. VoIP is a Layer 3 network protocol that uses various Layer 2 point-to-point protocols such as PPP for its transport. VoIP protocols typically use Real-time Transport Protocol (RTP) for the media stream or speech path. RTP uses User Datagram Protocol (UDP) as its transport protocol.

If you want to get a voice over IP service, you should find cheap VoIP services online.  You can find good VoIP phone service providers and VoIP rates if you do your research.  If you make a VoIP call, your voice goes through the following process:  Your voice in analog is sent from your regular telephone to an Analog Telephone Adapter.