Telecommunication Systems This paper will describe in general terms the telecommunication system currently in use at a private optometry clinic. The facility is owner operated with six employees and one location that provides a number of services to the public and area optometrist. This includes partnering with an optometry therapist to provide a full array of eye care services for pre and post eye surgery patients. Also included in this paper are short definitions of Rotary and Dual Tone Multifrequency (DTMF), Wide Area Telecommunications Service (WATS), Private Branch eXchange (PBX), and The layers of the International Organization for Standardization-Open Systems Interconnection (ISO-OSI), telecommunication terms as the relate to this business. Gaining permission to view and evaluate the telecommunication systems of a small family owned and operated business when you have been working there less than a week can be a tricky matter. I began by explaining that my interest in the system is purely school related. I continued by letting him know that the conversation and information exchanged could assist in developing a more effective system for the business. This helped but, skepticism and caution were still the overriding view of Doctor Martin business owner and board certified ophthalmologist. Ensuring the privacy of his business records appeared to relax him a bit as did telling him that I did not want any defined information just general. Telling him that I was not going to use his real name, the business name or any of the actual phone numbers in my paper also helped. With this assurance and the promise of a copy of the paper in place, he agreed to an interview on the telecommunication system used to support his optometry clinic.
The current telecommunication system As we began to talk about Doctor Martin’s optometry clinic and how his current telecommunication systems serviced the business, we started with the history of his business. Doctor Martin stated that he started with a small office in his home about forty years ago using an analog rotary phone and Plain Old Telephone Services (POTS) line. From there he moved to a clinic and shared a Dual Tone Multi-frequency (DTMF) system with Private Branch Exchange (PBX) that gave the small four doctor office a centered switch network with more lines to handle calls and an intercom system for paging and call holds. The clientele and suppliers were local to the area so the partners did not feel the need for an 800 or Wide Area Telecommunications Service (WATS). Upon leaving that group setting, Doctor Martin took out a lease on his current location. Here he uses a central office exchange system that provides his business with a four digit intercom number to connect and transfer calls to the internal examination rooms and main office, direct inward dialing (DID), 800 service, voice mail and caller ID. His internet access comes from the same provider using a shared T1 line. Receiving all of his communications services from one provider has helped him manage his costs as it gives him the ability to use social media to advertise his business. He stated that he likes his current location in a small strip mall and knows that his central office exchange system and T1 line is shared with the other eight stores in the complex. He thinks that losing some of the autonomy of a private system for a shared one is cost effective in that the provider is responsible for service repairs and equipment. System upgrades are offered by his provided that accommodates his business specific equipment at reasonable fees with minor interruptions for service changes and he believes CAT 5 wiring is in use throughout the system. We concluded this conversation with a question of data storage. Doctor Martin stated that he takes advantage of his provider offsite data storage option and runs nightly system backups with them and an additional private source.
Term Definitions
Rotary and Dual Tone Multifrequency (DTMF)
• Rotary refers to an analog system that uses a mechanical switch and a series of clicks to dial phone numbers through interrupted electrical pulses.
• Dual Tone Multifrequency (DTMF) is digital and instructs a phone switch system to dial a number using tones activated by pushing buttons on a key pad.
Wide Area Telecommunications Service (WATS) and leased lines
• WATS is a dedicated line and number that in-coming calls are routed through similar to an 800 number in use and ability but more cost effective based on call volume.
• Leased lines are dedicated connections between two parties or places that share information solely for the operation of their business. The advantage of a leased lines is traffic reduction as it is not public or used for general duties, speed and, control of data.
Private Branch eXchange (PBX) and Centrex
• Private Branch eXchange (PBX) is an in-house centered switching network used to handle both internal and external phone calls. It can also handle an internal intercom as all the equipment used is managed internally by the company using it.
• Central Office Exchange (Centrex) is similar to the PBX in function and services it provides but, the switching services and equipment are external to the company that uses it. The company providing the service owns, operates and maintains the equipment needed to run the system.
The layers of the International Organization for Standardization-Open Systems Interconnection (ISO-OSI) model
• International Organization of Standardization (ISO) is a non-governmental organization that developed standards of technological applications for global industry.
• Open Systems Interconnection (OSI) is a model that describes how information moves through a network. It is composed of seven layers with specific network functions. “Each layer performs a defined function for the layer above it and communicates with its peer layer over an interface”( Rowton, 2011). “Please Do Not Throw Sausage Pizza Away” is the phrase commonly used to remember the names and order of each layer. The layers are: • Physical – Bits
• Data Link – Frame
• Network – Packet
• Transport – Segment
• Session – Data
• Presentation – Data
• Application – Data

Reference
Rowton, Mitchell (2011) Open Systems Interconnection (OSI) Layers, Retrieved from
http://www.cisspzone.com/2011/04/open-systems-interconnection-osi-layers/