Companies referred to as providers provide VoIP services. Protocols used to carry voice signals over the IP network are referred to as Voice over IP or VoIP protocols. They are commercial realizations of the experimental Network Voice Protocol invented for the ARPANET providers. There are certain VoIP services which carry voice and data, where users have existing underutilized network capacity that can carry VoIP at no additional cost. VoIP to VoIP phone calls are sometimes free, while VoIP to PSTN may have a cost that is borne by the VoIP user. Keep in mind that there are two types of PSTN to VoIP services known as DID (Direct Inward Dialing) and access numbers. DID will connect the caller directly to the VoIP user while access numbers require the caller to input the extension number of the VoIP user.
Access numbers are usually charged as a local call to the caller and free to the VoIP user while DID usually has a monthly fee. There are also DIDs that are free to the VoIP user but chargeable to the caller. Voice over Internet protocol (VoIP) has been the latest solution in the search to cut costs. However, today contact centers that use VoIP are beginning to see other outcomes, especially increased flexibility. Things like an IVR application are cheaper to deploy in a VoIP setting than it is in a TDM setting. The VoIP telephone switch and servers are all working on the same network and talking the same language. The ability to have a centralized call center may also lead to an increase in the use of VoIP.
VoIP is growing in popularity, but its adoption has not been rapid. Contact centers have not been the leading adopters of [VoIP], because they are so well served by the legacy PBX vendors. However, the contact center operators who understand the value proposition of IP and how it can make your business better are going to jump to it as soon as they can. Stream International, a call center outsourcer that uses a hybrid IP/PBX deployment, is one firm that has made the decision to switch, but gradually, by adding VoIP functionality to its existing infrastructure. IP is now the preferred mechanism. VoIP is growing, but is it living up to all the hype? Probably not, due to the increased security requirements, the need to eliminate and reduce long distance charges as irrelevant in contact centers, and the home agent as not issues at all. Many organizations have yet to adopt it, because if it is just over the regular Internet, voice quality is not good. So what is next? Some say session initiated protocol (SIP) is the next step, but its hard to tell at this point.