
Telecom Terminology
Telecom Terms Made Easy?!
We have been in the telecommunications field for over 20 years are still amazed at the amount of acronyms and other industry terms that get thrown around as if everyone – including the client – knows them. In an effort to shine some light on some (certainly not all) terms we have written this list
CSR—In some circles this is simply a ‘customer service representative’ but in telecommunications this is a lengthy report from the phone company showing all of your services and charges. It appears that it is a foreign language when you first see one – do not be alarmed!
DID—Direct Inward Dial a method by where a company can purchase numbers (not lines) from the phone company and give employees private numbers. Usually transported through a PRI line (see below)
DSL—Digital Subscriber Line, the system used to push high speed data over an existing copper telephone line (see POTS). ADSL means that there is a different speed for downloads and uploads, SDSL means that the speeds are the same both directions.
Firewall – A device that can be programmed to allow or not allow data traffic to move in and out of a private network. It can either be software or hardware. For many businesses a software only solution is not recommended.
IP Telephony - a system that is fully IP has a server (either in a traditional phone cabinet, a router or a server) and IP telephone devices that connect to the server through a data switch.
Hosted IP/IP Centrex – these terms are interchangeable and refer to the ability for the phone company or other private provider to supply IP phone service and IP phones to a company without installing all of the controlling equipment at their location. This service is a rental service where a client would pay for phones/features on a per month basis the entire life of the contract. This is not an endorsement for this type of service, simply an explanation.
Hybrid—Not to be confused with the gas with corn in it. This is the classification of a phone system that can be programmed as a key system (see below) or as a traditional PBX (see below) or populated with IP functions.
Key System—This is a phone system programmed to show one button on a phone per one line connection from the phone company.
LAN—Local Area Network, a collection of computers or other devices connected in a single building through the use of hubs or switches.
LOA—Not to be confused with anything Hawaiian this is simply a ‘letter of authorization’ giving an appointed agent permission (from the customer) to interface, make changes, place orders on their behalf.
Number Portability – The ability to move your current phone number to another carrier. This can happen currently between cellular carriers providing service in the same regions. However, not all service providers in the local line arena can offer this feature at this time.
PBX—It refers to a sharing of line resources. On an individual phone there are no buttons designating individual line like in the Key System above. They typically dial ‘9’ to make phone calls outside of the building. Many systems today are referred to as IP-PBX systems because they use IP rather than digital or analog technology to drive the main processing.
PRI— a digital line that provides 23 application channels and 1 signaling channel. The 23 application channels can be shared for voice, data and video applications – depending on the installation. Commonly used is to replace multiple individual phone lines in a business for a streamlined cost.
Port—A spot where the cruise ships dock?! Actually, no this is an order to move existing phone numbers from those one for one telephone lines to a PRI (see above) so that a client does not lose existing telephone numbers and still streamlines cost.
POTS Line – it is a Plain Old Telephone Line run on copper cable usually provided by the local telephone company to a home or business.
Presence – a term used in the area of IP Telephony as well as other data circles such as instant messaging. It is the ability to quickly see the status of a user in a network – phone, data, or internet.
PSAP – Public Safety Answering Point many counties house full time 7x24 911 operators that are housed in this location. When a
T1/DS1—A 24 channel circuit that comes into a building on a single 4-pair copper cable. The total bandwidth of this line is 1.544 Mbps
VoIP- stands for Voice over Internet Protocol takes sound waves and touch tones and converts them to the 1’s and 0’s used in data transmissions.
WAN/MAN—Wide/Metropolitan Area Network, a method of connecting smaller LAN’s with organizations that have multiple sites on the same plot of land, throughout a city or across the country/state.


