How VoIP Works

Voice over Internet Protocol (VoIP) is the new buzzword in the telecoms industry. It stems from the philosophy that telephone voice calls are merely another type of data and can be sent over normal data lines, rather than over telephone lines. This philosophy of convergence means that you can use a single data line for all of your voice calls, internet and e-mail, as well as for television.

New technology and dropping inter-connect rates have led to many new changes and innovations in the market.

In 2010, ICASA forced a drop in inter-connect rates and for the first time, Voice over Internet Protocol (VoIP) offered clients significant savings over Local incumbent providers & traditional Premi-cell providers. There is little doubt today that Premicell is dead and that companies still using Local fixed-line incumbent and Premicells are wasting their money.

Today VoIP allows clients to route all their telephone calls − inter-branch, local, national, international and mobile. Because interconnect rates into the various networks keep dropping, a VoIP solution allows you to continuously take advantage of these rate drops.

voip works

Once in IP format, VoIP calls generally use a signaling protocol called SIP (Session Initiation Protocol) with a G.729 voice codec. A codec is a media format, which often allows compression. Because bandwidth is so expensive in South Africa, we use G.729, a voice compression system that allows you to send voice over Internet Protocol at about 16Kb per second (compressed without headers), rather than at 80kb per second in uncompressed format with headers.

Connecting the Dots

Once the voice call has been converted into SIP and G.729, the call is sent from your premises to Saicom Voice over data lines on an MPLS network (Multi Protocol Label Switching) to ensure quality and security. The size and type of data line used depends on the number of concurrent calls you wish to make and the quality required.

Incoming calls can also be sent to you via your VoIP link. We at Saicom Voice operate our own number ranges in both the 087 VoIP range, as well as through Geographic Number Ranges. You can also port your current number to us to handle it for you.

In order to use VoIP in your company, voice calls need to be in IP (Internet Protocol) format. If your Switchboard (PBX) is IP-enabled, your calls will already be in IP format. If your PBX is not IP-enabled, a VoIP Media Gateway needs to be attached to the PBX to convert the voice calls into IP format.