Converged telephone systems based on Voice over IP (VoIP) have matured to the point where organizations purchasing or upgrading telephone systems often select VoIP based systems. However, there are some important points to consider.

Call Quality
Because voice calls contend with data traffic on organizations’ networks, call quality is not guaranteed without taking certain steps. First and foremost, network gear needs to differentiate between packets containing voice and those with standard data such as email messages so voice can be prioritized. This is because a delay in transmitting voice noticeably impairs voice quality.

Network upgrades
Quality of service software is required to prioritize voice. However, older data switches often don’t have quality of service software and aren’t easily upgraded. In these instances, new switches for wiring closets and data centers are required. In addition, Power over Ethernet software is important so that all of the telephones can be powered and backed-up from the wiring closet rather than at outlets at each desk.

Data cabling for voice traffic
In VoIP systems, PC and telephone traffic share the same cabling. Personal computers plug into the back of each telephone, which is plugged into the data jack. VoIP traffic cannot run over lower grade cabling, which is often used for voice on traditional, older telephone systems. Sharing cabling with data is a huge advantage for organizations that need to connect buildings in a campus organization but have old or at capacity copper between buildings. It is the prime driver of many VoIP implementations.

Voice quality
New VoIP systems almost always need to be tweaked to improve voice quality. For example, echo cancellation often needs to be adjusted. In addition, a determination needs to be made to identify if voice problems are in local or long distance services or on-site equipment.

Links between data networks and VoIP telephones
Links to data networks make VoIP telephones easier to use and program. For example, users can program speed dial numbers and address books from their PCs rather than their telephone. In addition, calling internal staff is convenient because corporate directories can be viewed and automatically dialed from telephones’ LCD screens.

What are most organizations doing?
Older style, traditional telephone systems are generally reliable with good voice quality. However, organizations that need to replace aging telephone systems, accommodate growth or add systems for new locations are generally opting for VoIP or hybrid systems. Hybrid systems that support a mix of VoIP and traditional telephones are often used when organizations want to upgrade without discarding their entire system.

Why do it?
Small and medium sized organizations and those with robust LAN infrastructures often purchase VoIP systems, as do institutions that add specialized applications such as call centers. In addition, organizations with many mobile employees deploy it so staff can make and receive calls remotely using VoIP service.

The devil is in the details
The real difference between telephone systems that work well and those that don’t is the attention to details. Making sure everyone has the right model telephone, well-constructed contracts, the correct long distance and Internet connections, and training and documentation all ensure success. If not done properly, management headaches, disgruntled users and wasted staff time solving problems occur.