As a salesperson, it’s ironic that I spend a lot of time convincing people not to use Voice over IP (VoIP). It’s not that I don’t truly believe in the value of IP. Rather, I am a huge proponent for the “appropriate” use of IP, where it makes business sense and offers an appreciable ROI for the user.
IP was engineered as a best-effort, data networking system with inherent disaster recovery capabilities that the PSTN lacks. Most user are, or should be, more concerned with total availability, reliability and quality of service.
The traditional PSTN (Public Switched Telephone Network) is comprised of a two-level, circuit switched hierarchy of Class 5 (Local) and Class 4 (Long Distance) switches.
The local loop, or “subscriber line”, is the physical circuit connecting the customer (user) to their telecommunications service provider network. In a traditional PSTN carrier network, this local loop is terminated in a circuit switch maintained by an ILEC (Incumbent Local Exchange Carrier). The PSTN network for transporting phone calls has remained virtually unchanged, save for the introduction of electronic telephone exchanges in the mid 20th century.
To contrast, in a VoIP network the local loop is the same as the PSTN, but the transport mechanism underlying it is vastly different. IP communications transport backbones use an IP/MPLS infrastructure, technologies that were originally conceived for the transport of data, and have been adapted for voice transport.
If we state that the primary benefit of VoIP is cheaper telephone calls, which seems to be a popular statement these days, we are failing to illustrate the larger picture. The true promise of VoIP is that it should allow for the deployment of new services not possible on the traditional PSTN, and therein lies the true potential long term benefit for the majority of consumers and business users.
On the LAN side, the internal IP network that resides within most homes and offices today, VoIP offers significant business benefit and immediate ROI for most users. If you take a look at the basic feature set of practically any VoIP PBX….flexible auto attendant, voicemail/email integration, user call control, “presence”, support for remote workers, ease of administration….these are real benefits that many businesses lack today that can have a dramatic positive impact.
On the WAN side, calls coming in going out, there is often little, if any justification for the use of VoIP. As carriers and service providers mature, and begin to offer innovative features and services not previously viable on the traditional PSTN, they will create the proper justification and true ROI for both consumers and business users, and fully deliver on the promise of VoIP.