Many departments choose to purchase small communications systems with their additional system features. These departments require special features that the ESSX Service does not provide. Thus, electronic key or PBX systems are required. These systems have higher installation costs because the department purchases the hardware and software "up front." These systems are still interconnected with the ESSX Service for the purpose of provided extension dialing and access to SUNCOM and long distance services. These systems do have a limited service life as compared to the Single Line Concept system because the electronic key's and PABX's hardware and software will eventually fall short in providing adequate communications service for its owners in time. In some cases, these higher cost systems may save the departments in the medium term due to fewer ESSX lines terminated in the system if the departments' communications requirements allow the efficient use of fewer lines.
General
In certain cases, departments may require system features that are not provided by the single line concept. Even though Single Line Concept provides many line features, some UF users prefer a electronic key system with its available system features and multi-line/feature telephone. Electronic Key Systems have a higher installation cost as compared to single lines. This is because the customer must purchase the electronic computer based controller or key system unit (KSU) that typically resides in the communications closet/room. If voice mail is desired, it can be provided by ATT's Memory Call by installing a voice mail system as part of the key system. Upgrades to the electronic key systems are the responsibility of the owners of the equipment. UFIT Telecommunications maintains all telephone systems owned by the University. Electronic Key and PBX systems are no longer available for customers seeking new systems. Electronic key or PBX systems work best if the user prefers central answering in that all incoming calls are answered and processed by one or more positions. Automated Attendant can also be provided by electronic key systems to either back up the human answering positions or provide the main answering duties. Electronic key systems and PBX's are designed primarily for central answering. If one or more staff prefers to receive calls directly, additional ESSX lines can be installed for this purpose. The electronic key or PBX system can be programmed to switch any outside call using these "private lines" directly to the particular staff bypassing central answering. The department's overall call traffic allows the efficient sharing of ESSX lines. Fewer ESSX lines would be needed for the department. This situation reduces the monthly line costs for the department. Again, private lines can be provided, but they should be kept to a minimum. The department's existing and projected number of telephones number less than 120. Electronic key systems are limited in the number of telephone sets they can support. If the department's existing and projected number of stations number more than 120 and Single Line Concept will not do the job, Private Automated Branch Exchange (PABX) systems are available. PBX's initial costs are very high and only should be considered if there are no other alternatives. Both electronic key and PBX's have wireless technology that allows users to remain connected to their telephone systems even though they be on their feet in and about their building.