There are three major types of phone system available: KSU-Less phones, Key systems and Private Branch Exchange (PBX) systems. Which type of phone system you choose will depend on the amount of extensions you require and the features your telephone system needs to have installed.
KSU-Less systems are usually more suited to companies that typically have less than ten employees, or require less than ten extensions. That isn’t to say that all companies requiring less than ten phone extensions can make do with a KSU-Less system. It may be that you require more features which are only available through either a PBX or Key phone system.
Requiring a far lower initial investment than the other types of business phone systems, KSU-Less phones are specifically designed to include many of the features usually only available through the implementation of a full small business phone system.
KSU-Less systems can be easily unplugged and relocated, because they are not permanently wired into your office. This portability allows you to treat a KSU-Less phone system, much the same as any business machine, rather than a lost permanent investment.
You will need to ensure that any KSU-Less system you choose is compatible not only with the type of wiring you have in your office, but also with any accessories you may already have, such as: headsets, answering & fax machines and modems. Because KSU-Less phone systems are relatively inexpensive, they are not usually sold, installed, or maintained by telecoms vendors.
All of this means, you have to go out there and do not only the shopping yourself but, also the installation and support. This is one of the two major drawbacks of KSU-Less systems. The last thing any business needs is to be concerned with the reliability and maintenance of its phone system. Another drawback of KSU-Less systems is that they are more prone to something known as “crosstalk”. This is where separate conversations may blend into each other. With PBX, Key systems and Hybrid systems falling in price, it sometimes makes more sense to invest in a full business phone system, rather than become susceptible to the risks of a KSU-Less system.
Private Branch Exchange (PBX) systems
If your business typically requires more than forty extensions, or your needs dictate you need advanced functions from your business phone system, then PBX systems are often the solution. PBX systems used to be extremely expensive and only affordable by huge corporations with hundreds of extensions. Though this is still the case for larger installations, the development of the technology required has progressed to the point where a powerful, fully functional PBX office phone system for a small business is able to fit on the top of a desk.
Nearly all these compact PBX phone systems come with all the features you might want as standard. You pay a premium for the programmability and flexibility that a PBX offers, but in most cases the price difference is not as much as you may imagine between that of a less flexible phone system.
Key phone systems are more typical in businesses that require five to forty extensions. This type of phone system uses a central control unit called the Key System Unit (KSU) to provide features and functions that are not available using ordinary phones. An example of this is: key systems using a KSU allow one extension to call another in house extension, and prevents any other users from picking up a line that is already in use. Key systems usually come as standard with most features any business would expect, but in some cases they are often less flexible than a PBX phone system.
PBX & Key Systems (hybrids)
Though Key and PBX systems have some different technical features, these differences have become somewhat blurred over the past couple of years. Many Key systems now offer features that were once only available to those who chose to install a full PBX phone system. Some systems also operate internally as either a PBX or Key system depending on the software installed. Sometime these systems are often referred to as “Hybrid” phone systems.
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