VOIP or voice over Internet protocol is often associated with international calls or computer to computer calls. However, it may also be used in corporate environments as an alternative to PABX systems or to enable unlimited and free calling between two or more branches. It can also deliver fax messages depending on the VOIP equipment used.

Companies with multiple branches scattered in different provinces or regions may be able to reduce long distance charges by using VOIP for phone calls or for sending fax messages between branches. Because Internet service is already available in most cities and most companies are subscribing to the service, it makes sense to utilize the Internet service to avoid long distance charges for branch to branch calls. To do this, a VOIP gateway is used. The gateway converts voice or fax messages into data which is sent to the other branch’s VOIP gateway which converts it back to voice or fax.

VOIP gateways come in different models and features. Usually the ones that are capable of both fax and voice are more expensive than voice only gateways. Also, some gateways require an account from a VOIP provider in order to work. To be fully independent of third party services, companies should choose gateways that work directly with each other. And if high availability and reliability is a requirement, an industrial grade VOIP gateway should be used.

Companies with a need to deploy 25 or more telephone extensions and provide a computer network system, a very significant cost savings can be realized by deploying an IP-PBX instead of a regular PABX system together with the computer network. The cabling cost is significantly reduced because the IP-PBX system uses VOIP and can use the same network infrastructure as the computers. In regular PABX installations, each telephone extension needs to be wired back to the PABX system in the communications room. In a computer network, the use of manageable network switches reduces cabling cost because only one network cable is required to connect a large group of computers and IP-PBX extensions to the communications room. In the office area, a network switch is used to connect all the computers and IP-PBX extensions, requiring only short cable runs. Then one network cable is used to connect the switch to the communications room.

More savings can be realized in the equipment cost. A PABX system with voice mail, auto attendant and 100 extensions can easily cost around PHP 1,000,000 including installation and configuration. You can look at it as PHP 10,000 per extension. In an IP-PBX system, the cost of a VOIP phone that looks like a regular telephone unit is around Php 3,000 to 7,000, depending on features. The IP-PBX system itself is just a server grade computer which can cost from PHP 50,000 to PHP 100,000. The operating system and software are free (Linux and Asterisk). Installation and configuration can be negotiated with the contractor. The equivalent IP-PBX system will cost only half a regular PABX system. And in a local area network that is installed with standard specifications, latency and bandwidth problems are usually insignificant.

Lastly, an IP-PBX system can also be configured such that branches outside the local area network can still use the IP-PBX system via Internet connection. This enables corporations to deploy an IP-PBX system throughout all its offices and branches while retaining central control of the use of its communications resources.