Call Center-CallPath

Call Center

A place where calls are answered and calls are made. A call center will typically have lots of people (also called agents ), an automatic call distributor, a computer for order-entry and lookup on customers' orders. A Call Center could also have a predictive dialer for making lots of calls quickly. The term "call center" is broadening. It now includes help desks and service lines. Alcatel wrote a piece on them: "Call centers are the heart and soul of many businesses. They find new customers, create revenue, and help fix the problems of existing customers. Call centers are divided into two types, inbound and outbound. An inbound call center receives calls from current and potential customers for various reasons such as technical support, customer service, response to special offers, and order processing. Outbound call centers are generally geared to solicit new business (and/or collect outstanding bills). However, regardless of the function of the call center, they all have one thing in common, a centralized system to manage their internal workings. The centralized system to manage a call center will contain some or all of the following services to help customers reach agents and help agents manage their calls: + Specialized routing capability known as automatic call distribution (ACD), and (specialized commands for agents) including Log-on/log-off, Idle, In conversation, Wrap-up , Unavailable, Pause, Intrusion, Help and Silent monitoring.

Some larger call centers use more advanced technology such as interactive voice response (IVR), and multimedia capabilities such as co-browsing with a customer service specialist or engaging in a chat session. Routing and presenting of customer information to an agent has also become more sophisticated because of advances in computer telephony integration (CTI). ACD technology routed and queued calls on a first in, first out (FIFO) basis. Advances in this technology now allow a call to be routed based on the caller's telephone number, account number or even the number of times the caller was put on hold.

CTI advances now allow a full view of a customer's buying patterns, past encounters and opportunities to improve service. Customer relationship management (CRM) software is now tightly integrated in today's modern call center. Advances in IVR speech recognition enable customers to engage in some level of self-service, which adds up to happier customers and lower call volumes that must be handled by an agent. Finally, a well designed reporting and business intelligence system will provide agents, supervisors, and business managers with useful customer information to provide better customer services, to understand buying patterns, and to determine scheduling and service level goals. Better tools leads to more productive agents and ultimately happier customers."

For more information on Call Centers, please read Call Center Magazine. See also Call Centre .

Call Centre

A British term. An area in an organization where business is conducted by phone in a methodical and organized manner. Call centres are typically based on the integration of a computerized database and an automatic call distribution system. (Note that this definition contains British spellings.) See Call Center.

Call Clearing

The process by which a call connection is released from use.

Call Clear Packet

An information packet that ends an X.25 communications session, performing the equivalent of hanging up the phone.

Call Collision

  1. Contention that occurs when a terminal and a DCE simultaneously transfer a call request and an incoming call specifying the same logical channel. The DCE will proceed with the call request and cancel the incoming call.

  2. The condition that arises when a trunk or channel is seized at both ends simultaneously, thereby blocking a call.

Call Completion Rate

The ratio of successfully completed calls to the total number of attempted calls. This ratio is typically expressed as either a percentage or a decimal fraction.

Call Completion Service

An AIN (Advanced Intelligent Network) service which provides the Directory Assistance operator with the ability to automatically extend the call to the listed party. In a typical landline application, there is an additional charge to the calling party for such a service. (Frankly, I'd rather dial the number myself and save the 50 cents .) Cellular telephone providers often provide the service free of charge as a value- added service, in order to minimize "driving and dialing" traffic accidents. (I take advantage of this service ”It just makes sense.)

Call Control

Call control is the term used by the telephone industry to describe the setting up, monitoring, and tearing down of telephone calls. There are two ways of doing call control. A person or a computer can do it via the desktop telephone or a computer attached to that telephone, or the computer attached to the desktop phone line (i.e. without the actual phone being there). That's called First Party Call Control. Third-party call control controls the call through a connection directly to the switch (PBX). Generally third-party call control also refers to the control of other functions that relate to the switch at large, such as ACD queuing, etc.

Call Control Procedure

Group of interactive signals required to establish, maintain and release a communication.

Call Control Signal

Any one of the entire set of interactive signals necessary to establish, maintain, and release a call.

Call Control eXtensible Markup Language


Call Data

Call data refers to any data about a phone call that is passed by a switch to an attached computer telephony system. Call data is usually used by the computer telephony application to process the call more intelligently. Call data may be passed In- Band, over the same physical or logical link as the call ” usually via tones, or Out-Of- Band , over a separate link ” usually a serial link. Call data may also be passed as part of the data designed to control telephone networks, such as SS7 (Signaling System 7) links. In addition to information about the call, status about the call and even control over the call, can be available as part of the call data link services. Call data almost always includes what number dialed the call (ANI) and/or what number called (DNIS). More complex call data links used for "PBX integration" may also indicate why the call was presented (such as forwarded on busy), tell what trunk the call is coming in on or to pass message waiting on or off indications , and other functions. Full blown computer telephony links, such as are now being offered by many switching vendors , enhance the call data path , providing additional status information about calls. These links can even provide a level of call control to the attached computer telephony system. The above definition courtesy of Steve Gladstone, author of a great book called Testing Computer Telephony Systems, available from 212-691-8215.

Call Delay

The delay encountered when a call reaches busy switching equipment. In normal POTS telephone service, the delay is considered OK if no more than one and a half percent of the calls are delayed by three seconds during the busy hour .

Call Detail Recording

CDR. A feature of a telephone system which allows the system to collect and record information on outgoing and incoming phone calls ” who made/received them, where they went/where they came from, what time of day they happened , how long they took, etc. Sometimes the data is collected by the phone system; sometimes it is pumped out of the phone system as the calls are made. Whichever way, the information must be recorded elsewhere ” dumped right into a printer or into a PC with call accounting software. See also Call Accounting System.

Call Diverter

  1. A device which when connected to a called telephone number intercepts calls to that number and connects them to a telephone operator or prerecorded message.

  2. An ancillary device which is connected to a telephone line. The device will, when the called telephone rings, initiate a telephone call on another line to a different telephone number. The calling party may or may not be aware that his call has been diverted to another telephone.

Call Duration

The time from when the call is actually begun (i.e. answered) to the instant either party hangs up. Call Duration is an important concept for traffic engineering.

Call Establishment

The process by which a call connection is created.

Call Forward Busy

When your phone is busy, an incoming call is transferred to another number. That number might be one appearing on your phone system. It might be one at your home in the same city. It could even be in another city. Call Forward Busy can perform the same as Rollover Lines. I use Call Forward Busy to move calls from the first line of my residence to my second line, because my local phone company charges too much for Rollover Lines. (Don't ask why. They don't know either.) You can get Call Forward Busy from central offices, as well as PBXs and some key systems. See also Rollover Lines.

Call Forwarding

A service available in many central offices, and a feature of many PBXs and some hybrid PBX/key systems, which allows an incoming call to be sent elsewhere. There are many variations on call forwarding: Call forwarding busy. Call forwarding don't answer. Call forwarding all calls, etc.

Call forwarding is a useful feature. For example, you're going to a meeting but you're expecting an important call. Pick up your phone, punch in some digits and all your calls will go to the new number ” perhaps the phone outside the meeting room. The big disadvantage is that many people return to their offices but forget they forwarded their calls elsewhere. As a result, they usually miss a whole bunch of important calls. Some electronic phones now have a reminder light or message on them saying "all calls are being forwarded." Some people program their PBXs to cancel all call forwards at noon and at midnight every day. This makes sense.

Call forwarding is used to send calls to voice mail systems. For example, tell your PBX that if your phone isn't answered in four rings, send that call to your voice mail.

If you are getting call forwarding service from a central office in North America, the code to begin call forwarding is 72# and the number you want to be forwarded to. To cancel it, you punch in 73#.

Call Frame

Harris' PBX to computer link. Harris' protocol for linking its PBX to an external computer and having that computer control the movement of calls within a Harris PBX. See also Open Application Interface.

Call Gapping

A control application that limits the rate of flow to a specific destination code or station address.

Call Girls

One of the many colloquial names give to the early female telephone operators. Others include Hello Girls, Central, and Voice with a Smile.

Call Guide

A paper or screen "cheat sheet" that provides bullet points or actual copy for call center agents to use while they are on the telephone making marketing calls. They provide responses to commonly asked questions or objections in the most effective way. Call guides are excellent training tools as well as monitoring aids for coaches. See Call Guide Routing.

Call Guide Routing

The process by which a call center agent navigates through a call guide. The routing may be driven from a computer-based menu or function key or automatically by the computer system based on responses entered into a field.

Call Handoff

A cellular phone term. Call handoff happens when a wireless call is transferred to another cell site in mid-conversation.

Call Hold

If you hang the phone up, you lose the caller. Call hold ” a feature of most phone systems ” allows you to "hold" the call, so the other person can't hear you. You can then return to the conversation by pushing a button on your phone, typically the button flashing which shows which line the person is sitting on hold. Call hold is useful when you have someone on another line calling you.

Call Identifier

A network utility that is an identifying name assigned by the originating network for each established or partially established virtual call and, when used in conjunction with the calling DTE address, uniquely identifies the virtual call over a period of time.

Call In Absence Horn Alert

A cellular car phone feature that sounds your car's horn when you are receiving a call.

Call In Absence Indicator

A cellular car phone feature that ensures that power to the cellular phone is not lost if the car's ignition is turned off.

Call In Progress Override

A cellular car phone feature that keeps power to the phone during a call even though you've turned off the car's ignition.

Call Letters

Certain combinations of letters assigned to radio stations by the FCC. The group of letters assigned the U.S. by the International Radiotelegraph Convention are all three and four letter combinations beginning with N and/ or W and all combinations of KDA to KZZ inclusive.

Call Mix

Call mix is the pattern of call types (each call type defines what the caller will do for that call) that goes into creating a busy hour call profile or other call profile. A voice mail system's busy hour call profile call mix may consist of 10% call abandons, 20% login and send one message, 30% login and listen to one message, and so on. Varying the call mix can often be useful to stress particular parts of a system. For example, a call mix of 100% call abandons is frequently used to stress a computer telephony system's ability to handle high traffic call setup scenarios. This definition courtesy of Steve Gladstone, author of the book Testing Computer Telephony Systems, available from 212-691-8215.

Call Model

An abstraction of the call processing functionality of the architecture and the relationship that exists between the functionality of the Service Switching FE in an ASC and the Service Logic and Control FE in a SLEE (Service Logic Execution Environment). The call model consists of two components : Connection View and Basic Call State Model. Definition from Bellcore (not called Telcordia Technologies) in reference to Advanced Intelligent Network.

Call Not Accepted Signal

A call control signal sent by the called terminal to indicate that it does not accept the incoming call.

Call Notification Service

See Call Pickup Service.

Call Packet

A block of data carrying addressing and other information that is needed to establish an X.25 switched virtual circuit (SVC).

Call Park

The phone call is not for you. Or maybe it is, but you don't want to answer it on your phone. Put it into CALL PARK, then you or anyone else can answer it from any other phone. Call Park is similar to placing a call on hold, but you retrieve the call by dialing a code, rather than by pressing a line button. The attendant may have a call for you, but you're not there. So s/he places the call in Call Park, pages you and tells you the call is in Call Park. You pick up the nearest phone, dial one or two digits (the code for grabbing the call out of Call Park) and you have the call. It's faster than looking for you, then telling you to hang up while s/he transfers the call.

Call Pickup

A phone is ringing but it's not yours. With call pickup, you can punch in a button or two on your phone and answer that person's ringing phone. Saves time. See Call Pickup Group.

Call Pickup Group

CPUG. All the phones in an area that can be answered by each other by simply punching in a couple of digits. See Call Pickup.

Call Pickup Service

An AIN (Advanced Intelligent Network) service similar to those offered by many premise -based voice processors but residing on a network-based platform. In the event of an unanswered call, the voice processor records the call and notifies the called party of the message via pager, fax or some other technique.

Call Processing

The system and process that sets up the intended connection in a switching system. The system scans the trunk and/or station ports for any " requests " for service. Upon detecting a request, the system checks the stored instructions and look-up tables and sets the connection up accordingly .

Call Processing Language

See CPL.

Call Progress

The status of the telephone line; ringing, busy ring/no answer, voice mail answering, telephone company intercept, etc. See Call Progress Analysis and Call Progress Tone.

Call Progress Analysis

As the call progresses several things happen. Someone dials or touchtones digits. The phone rings. There might be a busy or operator intercept. An answering machine may answer. A fax machine may answer. Call progress analysis is figuring out which is occurring as the call progresses. This analysis is critical if you're trying to build an automated system, like an interactive voice response system.

Call Progress Signaling

All telephone switches use the same three general types of signals: + Event Signaling initiates an event, such as ringing. + Call Progress Signaling denotes the progress (or state) of a call, such as a busy tone, a ringback tone, or an error tone. + Data Packet Signaling communicates certain information about a call, for example, the identify of the calling extension, or the identity of the extension being called.

Call Progress Tone

A tone sent from the telephone switch to tell the caller of the progress of the call. Examples of the common ones are dial tone, busy tone, ringback tone, error tone, re-order , etc. Some phone systems provide additional tones, such as confirmation, splash tone, or a reminder tone to indicate that a feature is in use, such as confirmation, hold reminder, hold, intercept tones.

Call Queuing

Incoming or outgoing calls may be queued pending an answer. The idea of call queuing is to save money. See also Callback Queuing.

Call Rate

CR. The number of calls within a span of time, such as within an hour, or within a day, etc. It may be confined to a narrow usage, such as the busy hour (BH) originating call rate per main station, or to a broader usage. Hence, its usage should include enough modifying words to assure that it will be properly understood . A telephone company definition.

Call Record

The data record of a call transaction. The record is made up of event details that typically include date, time, trunk(s) used, station(s) used and duration. In an ACD, these events may also include time in queue, call route used, system disposition flag, inbound or outdialed digits and wrap-up data entered.

Call Reference

Information element that identifies to which call a Layer 3 message pertains.

Call Reference Value

CRV. A number carried in all Q.931 (I.451) messages, providing a local identifier for a given ISDN call. Also called Call Reference Number.

Call Release Time

The time it takes from sending equipment a signal to close down the call to the time a "free condition" appears and the system is ready for another call.

Call Reorigination

Caller reorigination allows a caller with a telephone debit card account number or a telephone credit card account to make unlimited calls without hanging up and redialing their access and their account numbers. At the end of the first call, the caller remains on the line. The caller then presses the pound key (the # key) for a prescribed number of seconds and receives a confirmation tone (which sounds like a high- pitched dial tone). After receiving the tone, the caller immediately dials their next phone number. And so on. Sometimes you can hit the # button after the person you were talking to has hung up. My experience has been that it's better to hit the # before the person has hung up. Just tell them what you're doing. All this allows the card account holder to make a series of calls without ever hanging up and redialing the often lengthy access card account numbers . This saves a lot of time for callers with a long list of calls to make. It also saves money for callers from hotels, which charge for each connection to the long distance provider, but don't charge based on the length of the call ( especially if it's a local call or toll-free 800 call). The prescribed number of seconds that the user needs to hold down the pound key is configurable. Depending on the application the time may range from 1 to 5 seconds. With most carriers , it's 2 to 3 seconds. The above definition was kindly provided by Karen Shelton, Systems Engineer, IEX Corporation, Richardson, TX.

Call Request Packet

In packet data switching, a call request packet carries information, such as sender and recipient identification, that is needed to establish an X.25 circuit. In more technical terms, a call request packet is sent by the originating data terminal equipment (DTE) showing the requested network terminal number (NTN), network facilities and either X.29 control information or call user data.

Call Restrictor

Equipment inserted in a telephone line or trunk which restricts outgoing calls in some way. Usually from making a toll call.

Call Return

An enhanced custom calling feature included in what are known as CLASS services and which are offered by local exchange carriers, courtesy of SS7. Call Return service which allows you to automatically dial the number of the last caller, even if you did not answer the telephone. It's a great idea, assuming that you are not blindly making long distance calls to long distance salespeople. Enhanced Call Return allows the called party to access a network-based voice system which announces the date, time and telephone number of the last incoming call. Should you chose to do so, you can launch Call Return by pushing a button on the telephone keypad.

Call Routing

A list of choices set up within an ACD (Automatic Call Distributor) where to send incoming calls.

Call Routing Tree

A graphical display of complex call routing decision logic.

Call Screening

There are several definitions. Here are two.

  1. A PBX feature that looks at the digits dialed by the caller to figure whether the call should be completed.

  2. A receptionist or secretary answers the executive's phone and checks that the person calling is important enough be put through to the almighty executive whose calls are being screened.

Call Second

A unit for measuring communications traffic. Defined as one user making one second of a phone call. One hundred call seconds are called "ccs," as in Centum call seconds. "ccs" is the U.S. standard of telephone traffic. 3600 call-seconds = 1 call hour. 3600 call-seconds per hour = 36 CCS per hour = 1 call-hour = 1 erlang = 1 traffic unit. See also Erlang and Traffic Engineering.

Call Selector

A local phone company service which alerts the subscriber with a distinctive ring that one of the six numbers your pre-selected is calling.

Call Sequencer

A call sequencer, also called an Automatic Call Sequencer, is a piece of equipment which attaches to a key system or a PBX. The Call Sequencer's main function is to direct incoming calls to the next available person to answer that phone. It typically does this by causing lights on telephones to flash at different rates. The light with the fastest flashing is the one whose call has been waiting longest. This call is answered first. Call Sequencers also might answer the phone, deliver a message and put the person on hold. They might keep statistical tabs of incoming calls, how fast they were answered, how long the people waited, how many people abandoned (hung up while they were on hold waiting for their call to be answered by a human being), etc. Call Sequencers are usually simple and inexpensive. Better, but much more expensive devices for answering incoming phone calls are Automatic Call Distributors. These are the devices which typically answer when you call an airline. See Automatic Call Distributor.

Call Setup

The first six PICs (Point In Call) of the Originating BCSM (Basic Call State Model), or the first four PICs of the Terminating BCSM. Definition from Bellcore (now called Telcordia Technologies) in reference to Advanced Intelligent Network.

Call Setup Time

The amount of time it takes for a circuit-switched call to be established between two people or two data devices. Call set-up includes dialing, wait time and time to move through central offices and long distance services. You don't pay for call setup, but you will need extra lines to take care of it. See also Answer Supervision and Traffic Engineering.

Call Shedding

In many states, laws require that a real-life breathing person be available for a phone call being outdialed with an automated device, e.g. a predictive dialer. The reason these laws were enacted is because a lot of times call-center managers have their predictive dialers going so crazy in search of real-life people answering the phone that, when they fluke it and actually hit a person, they don't have an agent ready. Most systems simply hang up the connection when this occurs and they mark it down for later calling. This is called "call shedding" and is illegal in many states.

Call Spill-over

In common-channel signaling, the effect on a traffic circuit of the arrival at a switching center of an abnormally delayed call control signal relating to a previous call, while a subsequent call is being set up on the circuit.

Call Splashing

A "splash" happens when an Alternate Operator Service (AOS) company, located in a city different to the one you're calling from, connects your call to the long distance carrier of your choice in the city the AOS operator is in. Let's say you're calling from a hotel in Chicago. You ask AT&T to handle your call. The AOS, located in Atlanta, "splashes" your call over to AT&T in Atlanta. But you're calling Los Angeles. Bingo. Your AT&T call to LA is now more expensive than it would be ” if you had been connected to AT&T in Chicago.

Call Splitting

A feature allowing a phone user to speak privately with either party of a conference call by alternating between the two. Call splitting by an attendant allows the attendant to speak to the called person privately while effectively putting the calling person on hold, or vice versa.

Call Stalker

An AT&T PC-based product which gives the 911 attendant the phone number and address of the person calling.

Call Store

The temporary memory used in a stored program control switch (SPC) to hold records of calls in progress. These records are then transferred to permanent memory.

Call Stream

British Telecom's premium rate service.

Call Tag

A term used in the secondary telecom equipment marketplace . A ticket directing a freight carrier (e.g., UPS) to pick up equipment at another site. The company issuing the ticket pays the freight charge. Normally used to return defective equipment, it ensures the dealer a quick return and an accurate tracking mechanism.

Call Teardown

The procedure of disconnecting a call between the central office and the subscriber.

Call Ticket

A report maintained by a manufacturer in its Technical Support Database that contains pertinent information on a single technical support issue as reported by a customer. Information typically includes: call tracking number (CTN), customer contact information, system configuration information, customer issue description, actions taken by manufacturer, actions suggested to and taken by customer, and a record of all customer contact events regarding the technical support issue.

Call Trace

A name for local telephone company service which permits the tracing of the last call received and holds the results for later use by an authorized law enforcement agency. (Results of the trace are not available to the customer.)

Call Tracking Number

CTN. Unique ticket number issued by a manufacturer of hardware or software and used for tracking the continuing status of an ongoing technical issue ” typically the customer is having a problem with his hardware or software.

Call Transfer

Allows you to transfer a call from your phone to someone else's. On some phones you do this by punching in a bunch of numbers. Some you do it by hitting the "transfer" button and then the number you want to send the call to. The fewer buttons and numbers you have to punch, the easier it will be for your people.

If you're choosing a telephone system, check how easy it is to transfer a call. It is the most commonly used (and misused) feature on a phone system. How many times have you been told, "I'll transfer you to Mr. Smith, but if we get disconnected, please call back on extension 234." If your people are saying this to your customers or prospects, you are giving the outside world the wrong impression of your business. And since 97% of your prospects' contact with your company is first through your phone system, you could be losing precious business.

Call Type

A call center term used in Rockwell ACDs. A portion of your call center traffic corresponding to one or more ACD gates or splits . This division of the total ACD traffic is the level at which forecasting and scheduling are done. At setup time, each Call Type is defined in the ACD by a unique three-letter code and specific gate or split number(s) that identifies the corresponding ACD report data.

Call User Data

In packet data networking technology, user information transmitted in a call request packet to the destination data terminal equipment (DTE).

Call Wading

Also known as Call Waiting, this feature allows you accept calls from, and talk to, additional callers during a conversation without any equipment other than an ordinary telephone. It is a CLASS feature for loop start lines. So called because once you have more than one call involved it becomes nearly impossible to know who you are talking to as you try to switch between (wade through) the calls. This feature is mostly called Call Waiting. See Call Waiting and CLASS.

Call Waiting

Call Waiting is a feature of phone systems that lets you know someone is trying to call you. You're speaking on the phone. A call comes in for you. You might hear a beep in your ear or see a light on your phone turn on. Or you might hear a beep and see a message come across the screen of your phone. When you hear the beep, you can, if you wish, put the present call on hold and answer the new one. You do this typically by hitting the touchhook on your phone (the cradle that sits under your handset.) Or you can ignore the new one, hoping it will go away, and perhaps send it to your attendant/operator, or voice mail. Call Waiting can be done manually by your telephone system operator. Or it can be a service which you buy monthly from your local phone company.

A major problem with call waiting is if you're on a data call from your PC, the call waiting "beep" will often cause your modem to hang up, thus destroying your data call. There are two solutions to this, the obvious one being to turn off call waiting. Some phone systems will allow you to turn it off. The way to turn it off is to include *70 in your modem dial string before you dial the phone number. That will tell your phone company (in most cases) to turn off the call waiting sound while you're on that (and only that) phone call. Another way is modify your modem's initialization string. Here's how. In all Hayes and Hayes-compatible modems, there's a S10 register. It tells the modem how long before it hangs up after losing carrier. In Hayes modems, the S10 register is set for 1.4 seconds. The typical call waiting tone is 1.5 seconds. Solution, increase the S10 register to six seconds (to be sure). Use your communications software. Go into terminal mode, then type: ATS10=60. You must put this command in every time you power up, because the Hayes 1200 modem (and others) have volatile memory. But the Hayes 2400 and higher speed asynchronous modems have non-volatile memory. They remember the six seconds after they've been switched off. The command to write this to memory is ATS10=60&W. The "&W" means write it to memory.


  1. A feature of some voice and data telephone systems. You dial someone. Their phone or computer is busy. You hit a button or code for "callback." When their phone becomes free, the phone system will call you and them simultaneously. You can only use this callback feature on things internally in your phone system ” calling other people, calling long distance lines (which might be busy), calling the dictation pool, etc. See Call Waiting, Callback Modem and Callback Queuing.

  2. A quick way of referring to international callback, which works thus: Calling the United States from many countries abroad is far more expensive than calling those countries from the United States. A new business called International Callback has started. It works like this. You're overseas. You dial a number in the United States. You let it ring once. It won't answer. You hang up. You wait a few seconds. The number you dialed in the U.S. knows it was you calling. There is a piece of equipment on that number that "hears" it ring and knows it's you since no one else has that number. (Typically it's done with Centrex service.) That was your special signal that you want to make a call. A switch attached to that line then calls you instantly. When you answer (overseas, obviously) it conferences you with another phone line in the United States and gives you U.S. dial tone. You can then touchtone from overseas your American number, just as if you would, were you physically in the U.S. There are huge savings. U.S. international callback operators can offer as high as 50% savings on calls from South America, where international calling rates are very high. The process of international callback is being automated with software and dialing devices. International callback is also helping to bring down the high cost of calling the U.S. from overseas. In recent years , deregulation has caused the price of international calls in many countries to fall dramatically. And now international callback or just callback is being done from other countries, including and especially Israel. A company called Kallback in Seattle, WA. has received a service mark from the U.S. Patent and Trademark Office for the words "callback" and "kallback" and sends letters to and threatens law suits against companies who use "their" words. See also Refile.

  3. A security procedure in which a user, dials into access a system and requests service. The system then disconnects and calls the user back at a pre-authorized number to establish the access connection. This capability is often implemented into a modem, known as a Callback Modem, surprisingly enough. Same as dial-back.

Callback Modem

A modem that calls you back. Here's how it works. You dial into a network. A modem answers. You put your password in. It accepts the password. It says "Please hang up. I will now call you back." You hang up. It calls you back. There are two reasons for doing this instead of allowing you to just go straight into the network.

  1. It's better security. You have to be at a pre-determined place ” an authorized phone number.

  2. It may save on phone calls. The modem uses the company's communications network, which is probably cheaper than what the person calling in can use.

Callback Queue

The queue used to hold callers who have requested a busy pool or extension. See Callback Queuing.

Callback Queuing

An option on a telephone system which allows outgoing calls to be put in line for one or several trunks. When a trunk becomes available, the phone system calls the user, his phone rings and then the phone system dials the distant party on the trunk it grabbed before calling the user. Phone systems typically have two types of queuing. The first is called Hold-On Queuing. With this, the user dials his long distance number, the phone system searches for the correct trunk, finds it's not available and tells the user with a beep or message. The user then elects to stay on the line and wait. The instant the trunk becomes free, the phone system connects the user to it. The second type of queuing is called Callback Queuing. The user hangs up and the phone system calls you back, as we explained above.

There are tradeoffs between the two types of queuing. Callback queuing obviously can tolerate longer queues. The longer you wait, the more chance you have of reaching a very low-cost trunk. But users don't like waiting so long for a trunk. And when the call does come, it may likely reach a phone, newly-deserted by a user who's gone to the bathroom.

In contrast, hold-on queuing is more efficient of the user's time, but less efficient of the user's trunks. The less time you wait, the less chance you have of reaching a low-cost trunk. Life is a trade-off. Queuing is no exception. See also Queuing.


Rolm (now Siemens) open architecture interface. A method of connecting a Rolm CBX (Siemens telephone system) to an outside computer, so that the computer may "talk" to the PBX and make certain things happen, e.g. moving a screen of client information around simultaneously with the phone call from the client. This feature is especially useful in customer service and customer order-entry environments ” for example with direct mail order catalog companies, etc. See Open Application Interface.

Called DTE

A DTE which receives a call from another DTE.

Called Line Identification Facility

A service feature provided by a network (private or public), which enables a calling terminal to be notified by the network of the address to which the call has been connected. See Caller ID.

Called Line Identification Signal

A sequence of characters transmitted to the calling terminal to permit identification of the called line.

Called Party Subaddress

Information element that is passed transparently by the SPCS (if certain conditions are met) and can be used to further identify the destination party.

Called Party Camp-on

A communication system service feature that enables the system to complete an access attempt in spite of issuance of a user blocking signal. Systems that provide this feature monitor the busy user until the user blocking signal ends, and then proceed to complete the requested access. This feature permits holding an incoming call until the called party is free.

Callender Switch

A very rudimentary, early telephone switching system developed by Romaine Callender and the Lorimer brother in the late 1800s.

Caller ID

Your phone rings. A name pops upon on your phone's screen. It's the name and number of the person calling you. Actually, it's the originating telephone number and the name the phone company thinks is the subscriber. The originating telephone number is stored in the originating central office equipment register, which is a database. That number supports a further database lookup, which associates the directory listing, assuming that the originating number is listed (i.e., not unlisted, or "nonpub" for nonpublished). The name and number information is passed through the local and long distance networks, and appears on your Caller ID box or your display telephone between the first and second rings.

The delivery of Caller ID information assumes several things. First, the entire network of switches must be supported by SS7 (Signaling System System #7). Second, the calling party must originate the call from a single-channel line, rather than a multichannel trunk (e.g., T-1). Third, the originating line/caller must not block the transmission of the information. If all of these criteria are not met, your Caller ID box will display "ANONYMOUS" or "NOT AVAILABLE." Caller ID is one of several CLASS (Custom Local Area Signaling Services) provided by your LEC (Local Exchange Carrier). There generally is both a small installation charge and a monthly charge for Caller ID. Caller ID lets you amaze your parents and scare your technophobic friends , when you answer the phone with something like "Hi, Harry! Great Dictionary!" Caller ID also helps you avoid those dinnertime calls from telemarketers . They always block their numbers. By the way, Caller ID is not the same as ANI, although they often are confused . See also ANI, Caller ID Message Format (for a very detailed explanation), and CLASS.

Caller ID Message Format

Calling Number Delivery (CND) came about as an extension of Automatic Number Identification (ANI). ANI is a method that is used by telephone companies to identify the billing account for a toll call. Although ANI is not the service that provides the information for CID, it was the first to offer caller information to authorized parties. The CID service became possible with the implementation of Signaling System 7 (SS7). The CID information is transmitted on the subscriber loop using frequency shift keyed (FSK) modem tones. These FSK modem tones are used to transmit the display message in American Standard Code for Information Interchange (ASCII) character code form. The transmission of the display message takes place between the first and second ring. The information sent includes the date, time, and calling number. The name associated with the calling number is sometimes included also. Since the time CID was first made available, it has been expanded to offer CID on Call Waiting (CIDCW) as well. With CIDCW, the call waiting tone is heard and the identification of the second call is seen. In earlier editions of my dictionary, I included the complete formatting, down to individual bits. It's too technical for this dictionary. However, if you want the entire story in all its detail, go to and read the article on "Caller ID Basics", by Michael W. Slawson of Intertek Testing Services, TestMark Laboratories. Michael has assured me that he will leave his excellent paper on the Web forever.

Caller Independent Voice Recognition

Having a voice response unit recognize the voice of a caller without having been trained on the caller's voice.

Caller Name

An enhancement of Caller ID. Prior to sending the originating telephone number to your display, the carrier associates that number with an electronic white pages listing, thereby transmitting both the originating number and the associated directory listing. Assuming that the number is listed and that the Caller ID number is not blocked, this provides a much better indication of the identity of the caller.


A procedure which consists of transmitting address signals in order to establish a link between devices that want to talk to each other.

Calling Card

A credit card issued by Bell operating companies, AT&T, MCI, Sprint and other phone companies (local and long distance) and used for charging local and long distance calls. Typically, the number on your calling card is the phone number at which you receive bills (home or business phone) plus a four digit Personal Identification Number (PIN). Increasingly often it's not. I prefer to carry a calling card with digits completely different to my phone number since this provides me with greater security. It's harder for someone to figure out my calling card. Some phone companies ” local and long distance ” charge more for a call made with a Calling Card. Some don't. Bell Canada claims they trademarked the term "Calling Card" in Canada. If they did, good luck protecting it, since the term "calling card" is generic. See Breakage, Debit Card and Prepaid Calling Card.

Calling DTE

A DTE (Data Terminal Equipment) which places a call to another DTE.

Calling Jack

In manual switchboard systems, the jack that is used by the operator to connect the call that came in through the answering jack, to the circuit for the subscriber who will be receiving the call.

Calling Line ID

Also called Caller ID. You are called. As the call comes in, you receive the phone number of the person calling you. See Caller ID for a full explanation. See also ANI, Calling Number Display, CLI, ISDN and Signaling System 7.

Calling Line Identification

See CLI and Calling Line ID.

Calling Line Identification Facility

A service feature, provided by a network, that enables a called terminal to be notified by the network of the address from which the call has originated. See Calling Line ID.

Calling List

A call center term. A collection of records from a database that is used for a specific telemarketing campaign. See Calling List Penetration.

Calling List Penetration

A call center term referring to outbound calls. The percentage of a call list for which the decision makers have been reached after a given number of attempts. See Calling List.

Calling Number

An international term for what Americans call "ANI" ” or automatic number identification. In other words, calling number simply tells you, the receiver of the call, who's calling. It tells you that by displaying the caller's number on the screen of your phone or the screen of your PC. And sometimes it might tell you who's actually calling. It can do that because some central offices (also called public exchanges) have the ability to dip into a database and replace the calling number with the name of the person who owns that phone number.

Calling Number Display

Your phone has a LCD (Liquid Crystal Display) or LED (Light Emitting Diode) display. When your phone rings, it will show which telephone number (internal or external) is calling you. Some phone systems allow you to add the person's name to the calling number display. See also ANI and Caller ID.

Calling Party

The person who makes (originates) the phone call.

Calling Party Camp-on

A feature that enables the system to complete an access attempt in spite of temporary unavailability of transmission or switching facilities. Systems that provide this feature monitor the system facilities until the necessary facilities become available, and then proceed to complete the requested access. Such systems may or may not issue a system blocking signal to let the caller know of the access delay.

Calling Party Control

CPC. Sometimes referred to as CPC Wink. A call supervision feature which provides the ability for a CO (Central Office) to signal the called party when the calling party hangs up. Some switches also provide CPC to the calling party when the called party hangs up. CPC allows the PBX, key system, or telephone answering device to reset the line so that it is ready to either accept or initiate another call. CPC is accomplished by either a loop current drop or reversal.

Calling Party Identification

A telephone company service which tells the person being called the number and sometimes the name of the person calling them. They can then decide to answer or not answer it. See ANI, which stands for Automatic Number Identification.

Calling Party Number

CPN. When a call is set up over an ISDN network, SS7 sends an IAM (Initial Address Message) as part of the ISUP (ISDN User Part) protocol. Included in the IAM is the Calling Party Number subfield, which contains the number of the calling party. Also included is a two-bit Presentation Indicator (PI), which indicates whether the terminating switch (cellular or PSTN) should pass the CPN to the called party. If the PI says "yes," the originating number is passed to the called party, who can see that number displayed on the telephone set or on an adjunct display device. The end result is Caller ID, perhaps also with the Caller Name, assuming that the called party has subscribed to those features. Based on recognition of the calling party, or the lack of it, Caller ID can prompt the called party to either accept or reject the call. See also Caller ID, Caller Name, IAM, ISUP, and SS7.

Calling Party Pays

In the United States, cell phone users pay for incoming as well as outgoing calls. In Europe and in most countries elsewhere, the calling party pays. According to many people, paying for incoming calls retards the industry's growth. As a result, there are many people in the U.S. cell industry, who would like this changed to "Calling Party Pays."

Calling Party Subdividers

Information element that is passed transparently by the SPCS (if certain conditions are met) and can be used to further identify the originating party. An AIN term.

Calling Pattern

Telecommunications managers are great at looking at phone bills, seeing patterns and smelling out calls that don't fit into those calling patterns. A simple example: zillions of calls over a weekend to Pakistan. The company doesn't do business with Pakistan. Nor does anyone work on the weekend .

Calling Sequence

A sequence of instructions together with any associated data necessary to perform a call.

Calling Tone

See CNG.


IBM's telephone system link to IBM's computers. See Callpath Coordinator, Callpath Services Architecture, Callpath Cics and Callpath Host.

Newton[ap]s Telecom Dictionary
Newton[ap]s Telecom Dictionary
ISBN: 979387345
Year: 2004
Pages: 133 © 2008-2017.
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