.jpg)
Telecom Industry Definitions
Here are definitions for terms used in the telecom industry.
Abandoned Call — A call into an ACD or IVR system where the caller hangs up before an agent answers.
ACD (Automated Call Distribution) — Device that automatically answers all incoming calls, sends the calls to the first available agent, or, if all agents are busy, plays a recorded message and places the call into a queue until an agent becomes available.
Analog Phone Line — Traditional telephone service (non-T1) whereby phone lines are delivered to the customer via copper wires. Each phone line requires two wires, and this service is typically associated with residential service or businesses that have fewer than 6 phone lines.
ANI (Automatic Number Identification) — The “called-from” phone number that is propagated through the public telephone network when a call is placed.
ARS (Automatic Route Selection) — Ability for a telephony system to route outbound calls based upon a pre-determined routing table which selects the most economical route. Sometimes referred to as “LCR” or Least Cost Routing.
ATA (Analog Telephone Adapter) — Device placed between an internet connection and a standard analog phone which turns a traditional telephony device into an IP device. Allows the user to utilize a traditional analog phone to place calls via VoIP over an internet connection.
Bell Operating Company (BOC) — Refers to any of the 22 original companies (or their successors) created when AT&T was broken up in 1983. The companies had been subsidiaries of AT&T and were called the “Bell System.” Each was given the right to provide local telephone service in a given geographic area. The purpose of the breakup was to create competition at both the local and long-distance service levels.
Busy Call-Forwarding — Feature provided by the local service provider that can be added to a phone line or hunt group whereby an incoming call is forwarded to an alternate number or voice mail when all lines are busy.
Busy Hour — A 60-minute period during which the average volume of telecommunications traffic is at its maximum.
Caller ID — The “called from” name and number that is transmitted and displayed over PSTN lines. The caller has the ability to block delivery of this information by dialing 67 before dialing the destination number.
Carrier — Telecommunications provider which owns or operates a long distance telephony network within the PSTN.
CAS (Channel Access Signaling) — Traditional type of call-control used on T1 lines where the on and off-hook signaling is transmitted over the same channel as the voice path (unlike PRI, ISDN, SS7, or SIP where the call control is transmitted via data channels or separate paths).
CLEC (Competitive Local Exchange Company) — Telephony company (not a Bell Operating Company) that competes for business in the local telephone market.
DID (Direct Inward Dial) — Inbound-only phone number assigned to a group of phone lines that allows a phone system to route to a unique location or person. A group of DIDs is often assigned to a single trunk group. DID numbers are not sent out as the ANI when the caller places an outbound call.
DNIS (Direct Number Identification Service) — Feature that sends all or part of the dialed number to a telephony system
DNC (Do Not Call) — National registry created to let consumers block incoming telemarketing calls. If you choose to add your phone number to this list, it shows up on the registry by the next day. Telemarketers have up to 31 days to remove your number from their call lists.
Hunt Group — Series of telephone lines organized so that when the first line is busy, the next line is “hunted” and so on until a free line is found.
IP (Internet Protocol) — Protocol on which the internet is based. It allows packets of data to traverse multiple networks on the way to its final destination.
IVR (Interactive Voice Response) — Telephony system that automatically answers incoming calls, provides greetings, menus, and prompts, then routes calls based upon the callers ANI or DTMF (dual-tone-multi-frequency, also known as touch-tone) digits received by the caller.
ISDN (Integrated Services Digital Network) — In the telephony world, ISDN is often interchanged with the term PRI (Primary Rate Interface) which is a T1 (group of 24 digital trunks) where the channels 1-23 are utilized for voice, and the 24th channel is utilized for call control.
Key System — Small digital phone system (usually 2-6 analog lines) that provides limited PBX functionality to a small number of users.
LEC (Local Exchange Carrier) — Local phone company, which can be either a Bell Operating Company or an independent, which traditionally had the exclusive right to provide local telephone service.
Local Number — Same as a telephone number. Any 10 digit LEC-assigned (non toll free) phone number that can be dialed from anywhere in the world. Includes all types of local numbers, such as ANIs, DIDs, and RCFs. If a caller must dial a “1” to reach this number, the caller is responsible for the per-minute costs.
LNP (Local Number Portability) — Ability of telephone subscribers to maintain their phone numbers when they change local telephone companies or toll free number providers.
MOS (Mean Opinion Score) — International standard that is used to measure the voice quality of a phone call. It uses a scale of 1 to 5, where 5 is the best quality . A score of 4.0 or better is considered PSTN or toll-quality.
NOC (Network Operations Center) — Secure and environmentally-controlled data center that houses critical telephony equipment and servers that are essential for operations.
NPA (Numbering Plan Area) — Area code (first 3 digits) of any 10 digit telephone number.
NXX — Digits 4, 5 and 6 of a 10 digit telephone number (often referred to as the “prefix”) where “N” is any digit 2-to-9. “X” is any digit 0-to-9. These digits typically identify the telephone company central office that serves that telephone number
PBX (Private Branch Exchange) — Large phone system that is capable of supporting hundreds or thousands of extensions. Can integrate a multitude of features (such as ACD, queue, voice mail, conferencing calling, etc.) and typically utilizes PRIs or VoIP to connect to the local service provider where incoming calls are routed utilizing DIDs.
POP (Point of Presence) — Any location where hardware that services a telephony network is located. Is a smaller version of a NOC.
POTS (Plain Old Telephone Service) Basic dial tone service provided via copper wires directly from the local service provider.
PRI (Primary Rate Interface) — A T1 (group of 24 digital trunks) where channels 1-23 are for voice, and channel 24 is for call control. Commonly found in larger phone systems or PBXs. There are many flavors of PRI.
PSTN (Public Switched Telephone Network) — Worldwide voice telephone network accessible to all those with telephones and access privileges.
QOS (Quality of Service) — In the telephony world, specifies the guaranteed throughput or quality of bandwidth used to route VoIP calls.
Queue — Telephony system that stacks or holds calls to be handled by a specific person or group. Often used in call centers, or with phone systems that handle large quantities of incoming calls.
RCF (Remote Call Forward) — Phone number assigned by the local phone company that has no physical location. When called, it forwards to another pre-determined phone number. The forward-to number can be changed only by the local phone company.
Redirect — Destination number associated with a toll free number. Is typically the customer’s main phone number.
RespOrg (Responsible Organization) — Telecommunications providers responsible for obtaining and managing toll free numbers from the Service Management System (national toll free routing database).
RNA (Ring-No-Answer) — Call that rang through to the destination, but was un-answered.
SIP (Session Initiation Protocol) — Internationally recognized IP telephony signaling protocol used for VoIP.
Signaling Gateway — Device that converts one type of telephony protocol to another. Often used with traditional telephony systems to allow them to utilize VoIP.
SMS800 Database — Service Management System database responsible for routing every toll free call made within North America. Contains information about which carrier will route the call, which RespOrg is responsible, and who the customer of record (the owner) is for each toll free number. Only RespOrgs are given direct access into this database.
Softswitch — High-density software-enabled approach to telephony switching that allows for rapid feature deployment and increased functionality within a switching platform. Has the potential to address all the shortcomings of traditional switches (scalability, smaller footprint, quicker feature creation, cost of operation, database integration, API, et al.).
SS7 (Signaling System 7) — International signaling standard for all digital exchanges with integrated services. Allows call control to be transferred on communications paths that are separate from the voice and data connections
Switch — Large-scale telephony platform used to route phone calls through the PSTN.
T1 — Dedicated phone or bandwidth connection that supports data rates of 1.54 Mbits per second. A voice T1 consists of 24 individual channels, each of which can be configured to support voice or data with up to 64k per second. The most common T1s are PRIs into PBXs configured as either local dial tone circuits or dedicated long distance circuits.
TCAP (Transaction Capability Application Part) — Portion of the SS7 protocol used to query databases and route calls according to the results. Used by every local service provider in North America to determine which carrier to route toll free calls to.
TFN (Toll Free Number) — 800, 866, 877, or 888 numbers that can be dialed from anywhere in North America, and are reverse-billed. The owner or company the TFN routes to is responsible for the per-minute costs, and the call is free of charge to the calling party. When dialing a TFN, the caller gives up their legal right of autonomy, and their phone number can be displayed to the called party, even if Caller ID block is enabled on the caller’s line.
TN (Telephone Number) — Same as Local Number. Any 10 digit LEC-assigned (non toll free) phone number that can be dialed from anywhere in the World. Includes all types of local numbers, such as ANIs, DIDs, and RCFs. If a caller must dial a “1” to reach the number, the caller is responsible for the per-minute costs.
Trunk — Phone line or voice path that can be used or shared across multiple voice applications.
VoIP (Voice over IP) — Process of transmitting voice traffic across a packet (data) network, typically utilizing SIP.
VPN (Virtual Private Network) — Private data network that makes use of the PSTN or internet, maintaining privacy through the use of a tunneling protocol and security procedures. This is often used in conjunction with VoIP as a more cost-affective alternative to a dedicated bandwidth connection.