A misconception because after all, VoIP and Internet Telephony use a completely different signalling system to traditional telephony. Therefore a different device must be required to convert those signals into the sounds that make up a telephone conversation. However, it is now possible to install a device; a VoIP gateway between the IP network and existing phone systems that converts the signalling from one to the other.

The VoIP gateway has two distinct roles. The first is to convert the signal so that a person using an IP device can talk to one on a traditional TDM device and vice versa. The second role is to manage the network signalling and routing.

For example, all IP devices, including phones, have an IP address while traditional telephones, even extensions on a company phone system, have their traditional telephone number. If a company has connected its traditional telephone system to an IP network, then incoming calls from the IP network will be looking for an IP address. The gateways job is to recognise the traditional telephone to which that IP address has been allocated and route the call accordingly.

This is just one simple example. Professional-class VoIP gateways, will translate all the sophisticated functions that have been developed in the traditional phone systems such as call forwarding and conferencing.

The better VoIP gateways also feature pass through. This function recognises the fact that for all its functional advantages and ability to save money, IP telephony is susceptible to catastrophic failure. For example, IP telephony requires a discrete power source, unlike the phones that will keep working even when the lights are turned off. For emergencies, therefore, an enterprise will want to keep at least one phone in each premise attached to the public switched telephone network (PSTN). For example with VegaStream's pass through this phone is connected the IP network until that network fails at which time it automatically connects to the PSTN.

The Benefits

Cost

With a VoIP gateway, a company can make telephone calls between sites at no cost using the IP data wide area network that it has installed to connects its computer systems. It can also use a gateway to connect its existing telephone systems to an Internet Telephony Service Provider (ITSP). ITSPs use the Internet to radically reduce customers telephone bills. In both scenarios, employees would use their telephones as normal. There is no training costs, just a significant reduction in the phone bill.

Flexibility

Enterprises are beginning to recognise the advantages of a fully converged communications solution. This is where all electronic communications voice, data, video, instant messaging and email all pass over a single network. This technology allows for highly efficient and content rich collaboration and interaction and is becoming the de facto standard in customer facing contact centres.

However, while there may be a strong business case for converged communications in the contact centre, the same may not be said for the broader organisation where the significant costs of the existing telephone system may yet to be written off. In these scenarios, the VoIP gateway will provide the solution for a company that wants to make a partial, and gradual, commitment to new converged technology, for example the company can mix and match traditional and IP telephone systems yet all use the telephones as usual.

The VoIP gateway is the essential bridge between todays telephone system and the future of converged communications.