Occasionally, you’ll see the word “convergence” come up in regards to phone systems. But what does it mean? In a word, flexibility.
Traditional, “old school” phone systems have always had two different types of ports: one type to support phone lines (dialtone), and another type to support the phones. Since all phones used to be analog phones, this second port type would also handle fax machines, credit card machines, and cordless phones, all of which have analog interfaces.
Over time, phone system manufacturers realized that they could increase flexibility and features by making digital phones rather than analog ones. Today, most phone system manufacturers who have been around for awhile offer digital phones. Because each manufacturer has its own idea of what would make for the best features in a phone system, its own “killer apps”, and implementation of features, these digital phones are proprietary and cannot move from one phone system type to another. Phone companies (dialtone providers), as well, realized that there were certain advantages to going digital, and began to offer digital phone lines. By far the most common of these is a T1 line, which can carry up to 24 conversations simultaneously. One flavor of T1 called ISDN/PRI is now the most popular due to it’s support of Caller ID (which a “plain” T1 does not support), and its enhanced signaling and troubleshooting capability (this is accomplished by having messages on the setup, progress, and teardown of calls take place on one of the 24 channels, leaving 23 available for voice conversations). Most phone system manufacturers now support T1/PRI.
In the last few years, we’ve seen the emergence of VoIP (or IP) phone technology, which promises to offer certain advantages over regular digital phones. The greatest of these is the ability to effortlessly move phones from one desk to another and keep the same extension, and the ability to use a phone off-premises and participate as if you were still in the office. This last item is significant, as it gives businesses flexibility to allow remote workers the ability to handle office calls just as if they were there in person. (There are actually several “flavors” or different types of VoIP, which is treated in a separate post.)
Even with the marvelous capabilities that IP phones enable, digital phones are here to stay for the foreseeable future. The reasons include, but are not necessarily limited to, IP phones being more expensive than their digital counterparts, and more potential for quality issues with VoIP. Some manufacturers have decided to keep their digital phone systems and IP phones separate, meaning that if you decide digital phones are best for you now, but would like to have IP phones in the future, you’ll need to upgrade the whole phone system. Other companies, typically ones who began life as data-driven companies such as Cisco, don’t offer digital (non-IP) phones. They mask their lack of experience and R&D in this arena by claiming that IP phones are the best solution in every situation.
Other companies, such as ESI (whose phone systems we sell), have decided to take a converged approach, meaning that their phone systems will support either digital or IP phones equally well, in any combination. If it makes sense for you to have digital phones inside the office (as we argue here is generally a good idea), and IP phones outside the office, you can do that. If you’d only like digital phones now but would like to add IP phones later, you can do that as well. In fact, ESI Communications Server phone systems support everything I’ve mentioned, including digital, IP or analog phones/devices, as well as analog lines or T1/PRI. It’s a great day we live in, and flexibility is the name of the game.
