Access Contention-ACO

Access Contention -ACO

Access Contention

In ISDN applications, synonymous with "contention." See contention.

Access Control

A technique used to define or restrict the rights of individuals or application programs to obtain data from, or place data into, a storage device. Similarly, access to system logic is controlled on the basis of appropriate Access Codes. See Access Code.

Access Control Field

  1. A term specific to Synchronous Multimegabit Data Service (SMDS), the Access Control Field controls access to the shared DQDB (Distributed Queue Dual Bus) which, in turn , provides access to the SMDS network. It consists of a single octet which is a portion of the 5-octet header of an SMDS cell . See also SMDS.

  2. A Token Ring term. A field comprising a single octet (eight bits) in the header of a Token Ring LAN frame. Three Priority (P) bits set the priority of the token, a single Token (T) bit denotes either token or a frame, a Monitor (M) bit prevents frames or high-priority tokens from continuously circling the ring, and three Priority Reservation r bits allow a device to reserve the token for network access the next time the token circles the ring. See also Token Ring.

Access Control List

ACL. Most network security systems operate by allowing selective use of services. An Access Control List is the usual means by which access to, and denial of, services is controlled. It is simply a list of the services available, each with a list of the computers and users permitted to use the service.

Access Control Message

A message that is a user request, a resource controller response, or a request/response between resource controllers.

Access Control Method

Set of rules which determine the basis on which devices are afforded access to a shared physical element, such as a circuit or device. In a Local Area Network environment, it regulates each workstation's physical access to the transmission medium (normally cable), directs traffic around the network and determines the order in which nodes gain access so that each device is afforded an appropriate level of access. By way of example, token passing is the technique used by Token Ring, ARCnet, and FDDI. Ethernet makes use of CSMA/CD or CSMA/CA; DDS makes use of a polling technique. See Media Access Control.(MAC).

Access Control System

A system designed to provide secure access to services, resources, or data; for computers, telephone switches or LANs.

Access Controls

An electronic messaging term. Controls that enable a system to restrict access to a directory entry or mailbox either inclusively or exclusively.

Access Coordination

An MCI definition. The process of ordering, installing, and maintaining the local access channel for MCI customers.

Access Coupler

A device placed between two fiber optic ends to allow signals to be withdrawn from or entered into one of the fibers.

Access Customer Name Abbreviation


Access Device

The hardware component used in the signaling controller system: access server or mux.

Access Envy

When I surf the web at two million bits per second (download) and you surf it at only 28,800 bits per second, you have a serious case of access envy, namely you envy my high speed.

Access Event

Telcordia definition for information with a logical content that the functional user and the Network Access FE (Functional Entity) exchange.

Access Floor

A system consisting of completely removable and interchangeable floor panels that are supported on adjustable pedestals or stringers (or both) to allow access to the area beneath .

Access Function

An intelligent network term. A set of processes in a network that provide for interaction between the user and a network.

Access Group

All terminals or phones that have identical rights to use the computer, the network, the phone system, etc.

Access Level

Used interchangeably with Access Code. "Level" in dialing tends to mean a number.

Access Line

A telephone line reaching from the telephone company central office to a point usually on your premises. Beyond this point the wire is considered inside wiring. See Local Loop and Access Link.

Access Link

The local access connection between a customer's premises and a carrier's POP (Point Of Presence), which is the carrier's switching central office or closest point of local termination. That carrier might be a LEC, IXC or CAP/AAV; in a convergence scenario, the carrier might also be a CATV provider.

Access List

List kept by routers to control access to or from the router for a number of services (for example, to prevent packets with a certain IP address from leaving a particular interface on the router).

Access Manager

  1. An element in some architecture implementations of a PCS infrastructure that includes functions such as subscriber registration and authentication. It may include the Home Location Register, HLR, and Visitor Location Register, VLR.

  2. A means of authorization security which employs scripting.

Access Method

The technique or the program code in a computer operating system that provides input/output services. By concentrating the control instruction sequences in a common sub-routine, the programmer's task of producing a program is simplified. The access method typically carries with it an implied data and/or file structure with logically similar devices sharing access methods. The term was coined, along with Data Set, by IBM in the 1964 introduction of the System/360 family. It provides a logical, rather than physical, set of references. Early communications access methods were primitive; recently they have gained enough sophistication to be very useful to programmers. Communications access methods have always required large amounts of main memory. In a medium size system supporting a few dozen terminals of dissimilar types, 80K to 100K bytes of storage is not an unusual requirement. The IEEE's 802.x standards for LANs and MANs. See Access Methods.

Access Methods

Techniques and rules for figuring which of several communications devices ” e.g. computers ” will be the next to use a shared transmission medium. This term relates especially to Local Area Networks (LANs). Access method is one of the main methods used to distinguish between LAN hardware. How a LAN governs users' physical (electrical or radio) access to the shared medium significantly affects its features and performance. Examples of access methods are token passing (e.g., ARCnet, Token Ring and FDDI) and Carrier Sense Multiple Access with Collision Detection (CSMA/CD) (Ethernet). See Access Method and Media Access Control.

Access Minutes

The term Access Minutes or Access Minutes of Use is used by NECA (the National Exchange Carrier Association) and the FCC in measuring traffic between LATA service providers (CLECs or ILECs) and IXCs (IntereXchange Carriers ). The formal definition is "Access Minutes or Access Minutes of Use is that usage of exchange facilities in interstate or foreign service for the purpose of calculating chargeable usage. On the originating end of an interstate or foreign call, usage is to be measured from the time the originating end user's call is delivered by the telephone company and acknowledged as received by the interexchange carrier's facilities connected with the originating exchange. On the terminating end of an interstate or foreign call, usage is to be measured from the time the call is received by the end user in the terminating exchange. Timing of usage at both the originating and terminating end of an interstate or foreign call shall terminate when the calling or called party disconnects, whichever event is recognized first in the originating or terminating end exchanges, as applicable ." This comes from the FCC's 69.2 Definitions.

Access Network

Several wholesale carriers define access network as the fiber connection and associated electronic equipment that link a core network to Points of Presence (POPs) and on to Points of Interconnect (POIs) switch locations.

Access Node

Access nodes are points on the edge of a network which provide a means for individual subscriber access to a network. At the access node, individual subscriber traffic is concentrated onto a smaller number of feeder trunks for delivery to the core of the network. Additionally, the access nodes may perform various forms of protocol conversion or adaptation (e.g. X.25, Frame Relay, and ATM). Access nodes include ATM Edge Switches, Digital Loop Carrier (DLC) systems concentrating individual voice lines to T-1 trunks, cellular antenna sites, PBXs, and Optical Network Units (ONUs).

Access Number

The telephone number you use to dial into your local Internet Service Provider (ISP). To connect to the Internet you must first establish an account with an ISP in your area. Usually you will receive a list of telephone numbers you can use to "dial-in" to the service.

Access Organization

An entity which originates program material for transmission over the access channel capacity of a cable television system. An access organization may be an individual, a non-profit corporation, an unincorporated non-profit association, or a for-profit corporation. However, under most cable franchises, commercial advertising is prohibited on Public, Educational, and Government Access channels.

Access Phase

In an information-transfer transaction, the phase during which an access attempt is made. The access phase is the first phase of an information-transfer transaction.

Access Point

  1. A point where connections may be made for testing or using particular communications circuits.

  2. A junction point in outside plant consisting of a semipermanent splice at a junction between a branch feeder cable and distribution cables.

  3. AP. A cross-box where telephone cables are cross connected.

  4. Network device that interconnects a wireless radio network to a wired LAN (local area network).

Access Protection

Refers to the process of protecting a local loop from network outages and failures. Access protection can take many forms, such as purchasing two geographically diverse local facilities, adding protection switches to the ends of geographically diverse local loops , or buying service from a local access provider which offers a survivable ring-based architecture to automatically route around network failures.

Access Protocols

The set of procedures which enable a user to obtain services from a network.

Access Provider

A company, such as a telephone company, that hooks your computer up to the Internet.

Access Rate

  1. The maximum data rate of the access channel, typically referring to access to broadband networks and network services.

  2. AR. A Frame Relay term which addresses the maximum transmission rate supported by the access link into the network, and the port speed of the device (switch or router) at the edge of the carrier network. The Access Rate defines the maximum rate for data transmission or receipt. See also Committed Information Rate.

Access Request

A message issued by an access originator to initiate an access attempt.

Access Response Channel

ARCH. Specified in IS-136, ARCH carries wireless system responses from the cell site to the user terminal equipment. ARCH is a logical subchannel of SPACH (SMS (Short Message Service) point-to-point messaging, Paging, and Access response CHannel), which is a logical channel of the DCCH (Digital Control CHannel), a signaling and control channel which is employed in cellular systems based on TDMA (Time Division Multiple Access). The DCCH operates on a set of frequencies separate from those used to support cellular conversations. See also DCCH, IS-136, SPACH and TDMA.

Access Router

An access device with built-in basic routing-protocol support, specifically designed to allow remote LAN access to corporate backbone networks. An access router is not designed to replace backbone routers or to build backbone networks.

Access Server

Communications processor that connects asynchronous devices to a LAN or WAN through network and terminal emulation software. Performs both synchronous and asynchronous routing of supported protocols. Sometimes called a network access server.

Access Service

Switched or Special Access to the network of an IXC for the purpose of originating or terminating communications.

Access Service Ordering Guidelines

ASOG. Industry guidelines for issuing Access Service Requests (ASRs) as sponsored by the Ordering and Billing Forum (OBF) and the Alliance for Telecommunications Industry Solutions (ATIS). These guidelines outline the forms, data elements and the business rules necessary to create an Access Service Request.

Access Service Request

ASR. A form used by a CLEC (Competitive Local Exchange Carrier) to request that the ILEC (Incumbent LEC) provide Special Access or Switched Access Services as specified in the various Access Service Tariffs. Some services that can be requested are: Feature Group A, WATS Access Line; Feature Groups B, C, D Forms; special access circuits; multipoint service legs; additional circuits; testing service; and 800 database access. The ASR has been used for many years between the RBOCs (regional Bell operating companies) to order special circuits that extend into other telcos' serving areas.

Access Signaling

A term which Nortel Networks' Norstar telephones use to indicate their ability to access a remote system (such as a Centrex or a PBX), or dial a number on an alternate carrier by means of Access Signaling (also referred to as "End-to-End" Signaling).

Access Surcharge

State specific usage charges applied to dedicated lines on the originating end of a circuit.

Access Switch

Feeder node to Enterprise Network Switches that perform multiprotocol bridge/routing and support a wide range of serial-link (e.g., SDLC BSC, asynchronous) attached devices. Also known as Gateways, such devices currently are known as Routers and Encapsulating Bridges, although the differences between them are most significant.

Access Tandem

A Local Exchange Carrier switching system that provides a concentration and distribution function for originating and/or terminating traffic between a LEC end office network and IXC POPs. In short, a distinct type of local phone company switching system specifically designed to provide access between the local exchange network and the interexchange networks for long-distance carriers in that area. The Access Tandem provides the interexchange carrier with access to multiple end offices within the LATA. More than one Access Tandem may be needed to provide access to all end offices within any given LATA. Currently, the Access Tandem function may be in the form of a physical and logical partition of a LEC Central Office switch, which also serves end users for purposes of satisfying local calling requirements. Additionally, the IXC may extend the reach of the POP through a high-speed channel extension via dedicated circuits, thereby achieving interconnection with the LEC though collocation of termination facilities in the LEC CO.

In its internal glossary, US West defines Access Tandem as the switching system that provides distribution for originating or terminating traffic between End Offices and the Interexchange Carrier's Point-of-Termination. An Access Tandem is also used to distribute originating or terminating traffic between a CLEC end office and an intraLATA toll point or an Interexchange Carrier's Point of Termination.

Access Time

There are many definitions of access time:

  1. In a telecommunications system, the elapsed time between the start of an access attempt and successful access. Note: Access time values are measured only on access attempts that result in successful access.

  2. In a computer, the time interval between the instant at which an instruction control unit initiates a call for data and the instant at which delivery of the data is completed.

  3. The time interval between the instant at which storage of data is requested and the instant at which storage is started.

  4. In magnetic disk devices, the time for the access arm to reach the desired track and for the rotation of the disk to bring the required sector under the read-write mechanism.

  5. The amount of time that lapses between a request for information from memory and the delivery of the information, usually stated in nanoseconds (ns). When accessing data from a disk, access time includes only the time the disk heads take to settle down reaching the correct track (seek time) and the time required for the correct sector to move over the head (latency). Disk access times range between 9ms (fast) and 100 ms (slow).

  6. A Verizon definition: Access time (usage) is measured from the time that the originating customer's call is delivered by the Telephone Company to, and acknowledged as received by, the receiving customer's equipment when they are connected with the originating exchange. On the terminating end of an interstate or foreign call, access time is measured from the time the call is received by the end user in the terminating exchange. Access ends when the calling or called party disconnects.

Access Unit

  1. AU. An electronic messaging term, used for implementing value-added services such as fax, Telex, and Physical Delivery via X.400.

  2. In the token ring LAN community, an access unit is a wiring concentrator. See Media Access Unit (MAU).


Access Overload Class. A term used in the cellular phone business to allow the cellular system some way of choosing which calls to complete based on some sort of priority. Originally, when the Federal government began designing cellular systems, the government intended to give certain emergency vehicles (such as police, ambulances, and fire departments) codes in their cellular phones that would allow them priority over other subscribers to communicate during emergencies. There is no standard in use within the United States at this time.


On LANs or multiuser operating systems, an account is given to each user for administrative and security reasons. In online services, an account identifies a subscriber.

Account Code (Voluntary or Enforced)

A code assigned to a customer, a project, a department, a division ” whatever. Typically, a person dialing a long distance phone call must enter that code so the Call Accounting system can calculate and report on the cost of that call at the end of the month or designated time period. Many service companies, such as law offices, engineering firms and advertising agencies use account codes to track costs and bill their clients accordingly . Some account codes are very complicated. They include the client's number and the number of the particular project. The Account Code then includes Client and Matter number. These long codes can tax many call accounting systems, even some very sophisticated ones.

Account Executive

AE. A fancy, schmancy name for a salesperson. The idea is that the customer is an "account," and the salesman is the executive running the account. Telephone companies call their salespeople account executives ” especially on the equipment and non-long distance side.

Account Policy

On networks and multiuser operating systems, account policy is the set of rules that defines whether a new user is permitted access to the system and whether an existing user is granted additional rights or expanded access to other system resources. Account policy also specifies the minimum length of passwords, the frequency with which passwords must be changed, and whether users can recycle old passwords and use them again.


Someone who figures your numbers, then numbers your figures and then sends you a bill. See also Economist.

Accounting Management

In network management, a set of functions that enables network service use to be measured and the costs for such use to be determined and includes all the resources consumed, the facilities used to collect accounting data, the facilities used to set billing parameters for the services used by customers, maintenance of the data bases used for billing purposes, and the preparation of resource usage and billing reports .

Accounting management is one of five categories of network management defined by ISO for management of OSI networks. Accounting management subsystems are responsible for collecting network data relating to resource usage. See also configuration management, fault management, performance management and security management.

Accounting Rate System

This fading system governs the sharing of revenues received by telephone companies for international calls. Carriers would bilaterally agree on an accounting rate applicable on an international route. The accounting rate would then be split in half, with the so-called settlement rate being passed on to the carrier receiving the call. Controversy and opposition to accounting rates have arisen because they have not been cost-driven. instead, they were used to cross-subsidize cheaper domestic call rates. The realignment of rates that has accompanied deregulation is known as rebalancing. Generally, the United Kingdom, Germany, France, Scandinavia, and Switzerland have rebalanced their tariffs. Spain, Portugal, and Greece still have a way to go. This is how it used to work: If AT&T sends France Telecom one million minutes of calls, but France sends only 500,000 minutes back to AT&T, then AT&T will have to pay France Telecom for the imbalance. If the accounting rate between France and the United States is $1 per minute, then AT&T will pay France Telecom $250,000 for its work in completing the 500,000 extra calls. AT&T pays France Telecom only half the cost because AT&T does half the work itself.

Accounting Servers

A Local Area Network costs money to set up and run. Thus it may make sense to charge for usage on it. In LANs which rely on the Novell NetWare Network Operating System, the network supervisor sets up accounting through a program called SYSCON. When this happens, the current file server automatically begins to charge for services. The supervisor can authorize other network services (print servers, database servers, or gateways) to charge for services, or can revoke a server's right to charge.

Accounting Traffic Matrix

A mobile term. A traffic matrix is a collection of information, gathered over a period of time, containing statistics on Mobile End System (MES) registration, de-registration, and Network Protocol Data Unit (NPDU) traffic.


Automatic Calling Card Service.


  1. A register in which one operand can be stored and subsequently replaced by the result of an arithmetic or logic operation. A term used in computing.

  2. A storage register.

  3. A storage battery.


Absence of error. The extent to which a transmission or mathematical computation is error-free. There are obvious ways of measuring accuracy, such as the percentage of accurate information received compared to the total transmitted.

AC/DC Ringing

A common way of signaling a telephone. An alternating current (AC) rings the phone bell and a direct current (DC) is used to work a relay to stop ringing when the called person answers.


See the next seven definitions, ACD, Automatic Call Distributor and ACIS.

ACD Agent

A telephony end user that is a member of an inbound, outbound, skills based, or programmable Automatic Call Distribution group. ACD Agents are distinguished from other users by their ability to sign on (i.e., login) to phone systems that coordinate and distribute calls to them.

ACD Agent Identifier

The identifier of an ACD agent. An agent identifier uniquely identifies an agent within an ACD group. See ACD Agent.

ACD Application Bridge

Refers to the link between an ACD and a database of information resident on a user's data system. It allows the ACD to communicate with a data system and gain access to a database of call processing information such as Data Directed Call Routing.

ACD Application-Based Call Routing

In addition to the traditional methods of routing and tracking calls by trunk and agent group, the latest ACDs route and track calls by application. An application is a type of call, e.g. sales vs. service. Tracking calls in this manner allows accurately reported calls especially when they are overflowed to different agent groups.

ACD Call Back Messaging

This ACD capability allows callers to leave messages for agents rather than wait for a live agent. It helps to balance agent workloads between peak and off-peak hours. In specific applications, it offers callers the option of waiting on hold. A good example is someone who only wishes to receive a catalog. Rather than wait while people place extensive orders, they leave their name and address as a message for later follow-up by an agent. This makes things simpler for them and speeds up service to those wanting to place orders.

ACD Caller Directed Call Routing

Sometimes referred to as an auto attendant capability within the industry, this ACD capability allows callers to direct themselves to the appropriate agent group without the intervention of an operator. The caller responds to prompts (Press 1 for sales, Press 2 for service) and is automatically routed to the designated agent group.

ACD Central Office

An Automatic Call Distributor (ACD), usually located in a central office and supplied to the customer by the telephone company (telco) with tariffed pricing structures. Some data gathering equipment is often located on customer premises.

ACD Conditional Routing

The ability of an ACD to monitor various parameters within the system and call center and to intelligently route calls based on that information. Parameters include volume levels of calls in queue, the number of agents available in designated overflow agent groups, or the length of the longest call. Calls are routed on a conditional basis. "If the number of calls in queue for agent group #1 exceeds 25 and there are at least 4 agents available in agent group #2, then route the call to agent group #2."

ACD Data Directed Call Routing

A capability whereby an ACD can automatically process calls based on data provided by a database of information resident in a separate data system. For example, a caller inputs an account number via touch tone phone. The number is sent to a data system holding a database of information on customers. The number is identified, validated and the call is distributed automatically based on the specific account type (VIP vs. regular business subscriber, as an example).


A Nortel term for an Automatic Call Distribution Directory Number (ACD DN), which refers to the queue where incoming calls wait until they are answered. Calls are answered in order in which they entered the queue.

ACD Group

Multiple agents assigned to process incoming calls that are directed to the same dialed number. The ACD feature of the telephone switch routes the incoming to one of the agents in the ACD group based upon such properties as availability of the agent and length of time since the agent last completed an incoming call.

ACD Intelligent Call Processing

The ability of the latest ACDs to intelligently route calls based on information provided by the caller, a database on callers and system parameters within the ACD such as call volumes within agent groups and number of agents available.

ACD Number

The telephone number that calling devices dial to access any of the multiple agents in an ACD group. Once the incoming call arrives at the ACD number, the ACD service can then route the call to one of multiple agents in the ACD group.

ACD Skills-Based Routing

See Skills-Based Routing.


Above ground Cable Enclosure.


Algebraic Code Excited Linear Prediction. A variation of CELP. ACELP improves on the efficiency of CELP voice compression by a factor of 2:1, thereby yielding good quality voice at only 8 Kbps, as compared to CELP at 16 Kbps, and PCM at 64 Kbps. ACELP accomplishes this minor miracle through the use of a code book which contains algebraic expressions of each set of voice samples, rather than expressions of each set as a series of numbers. ACELP has been standardized by the ITU-T in G.723.1 (Dual Rate Coder for Multimedia Communications), and in G.729 as CS-ACELP (Conjugate Structure-ACELP). Proprietary versions also exist. The Frame Relay Forum has specified ACELP in FRF.11 IA (Implementation Agreement) as one of the minimum voice compression algorithms required for network-to-network interoperability in VoFR (Voice over Frame Relay) applications. See CELP for the full background on ACELP. See also CS-ACELP, Dual Rate Speech Coder for Multimedia Communications, LD-CELP, and VoFR.


Advanced Communication Function. A family of software products used by IBM allowing its computers to communicate.


Advanced Communication Function/ Network Control Program. In host- based IBM SNA networks, ACF/NCP is the control software running on a communications controller that supports the operation of the SNA backbone network.


Advanced Communication Function/Virtual Terminal Access Method. In host-based IBM SNA networks the ACF/VTAM is the control software running on a host computer that allows the host to communicate with terminals on an SNA network.


Short for AutoConFiGuration. The Plug and Play BIOS extensions, now turning up on PCs, are also known as the ACFG BIOS extensions.


Attempts per Circuit per Hour. This is a term you often see in call centers. It refers to the number of times someone tried to reach a circuit in one hour. In a normal phone system, ACH refers to the number of times someone tried to make a call on a circuit in one hour. Measuring ACH is useful for figuring how many inbound or outbound trunks you may need. See also CCH, which is connections per hour .


Acid is an acronym for the four characteristics of a database transaction done correctly over a network ” private or the Internet. For the transaction to be considered valid, it must be:

  • Atomic; The transaction should be done or undone completely. In the event of a failure (network, or system) all operations and procedures should be undone. And all data should be able to be rolled back to its previous state.

  • Consistent: A transaction should transform a system from one consistent state to another consistent state.

  • Isolation: Each transaction should happen independently of the other transactions occurring at the same time.

  • Durable: Completed transactions should remain permanent, even during a network or system failure.


Australian Communications Industry Forum, established in May, 1997 as a communications industry self-regulatory body. The ACIF is responsible in Australia for developing standards, codes of practice and service applications.


Automatic Customer/Caller Identification. This is a feature of many sophisticated ACD systems. ACIS allows the capture of incoming network identification digits such as DID or DNIS and interprets them to identify the call type or caller. With greater information, such as provided by ANI, this data can identify a calling subscriber number. You can also capture caller identity by using a voice response device to request inbound callers to identify themselves with a unique code. This could be a phone number, a subscriber number or some other identifying factor. This data can be used to route the call, inform the agent of the call type and even pre-stage the first data screen associated with this call type automatically. See also ANI, Caller ID and Skills-Based Routing.


In data communications, ACK is a character transmitted by the receiver of data to ACKnowledge a signal, information or packet received from the sender. In the de facto standard IBM Binary Synchronous Communications (also known as BSC or Bisync) protocol, an ACK is transmitted to indicate the receipt of a block of data without any detected transmission errors. This positive acknowledgement reassures the transmitting device of that fact in order that the next block of data may be transmitted. Binary code for an ACK is 00110000. Hex is 60. See also Acknowledgment.

ACK Ahead

A variation of the XMODEM protocol that speeds up file transmission across error-free links. See XMODEM.


Bisync acknowledgment for odd-numbered message.


In data communications, the transmission of acknowledgment (ACK) characters from the receiving device to the sending device indicates the data sent has been received correctly.


  1. Access Control List. A roster of users and groups of users, along with their rights. See Access Control List.

  2. Applications Connectivity Link. Siemens' protocol for linking its PBX to an external computer and having that computer control the movement of calls within a Siemens PBX. See also Open Application Interface.


  1. An ATM term. Address Complete Message. One of the ISUP call set-up messages. A message sent in the backward direction indicating that all the address signals required for routing the call to the called party have been received. See ATM.

  2. Association for Computing Machinery.

  3. Automatic Call Manager. The integration of both inbound call distribution and automated outbound call placement from a list of phone contacts to be made from a database. Telemarketing and collections applications are targets for this type of system.


Access Customer Name Abbreviation. A three-digit alpha code assigned to identify carriers (including both ILECs and CLECs) for billing and other identification purposes. If your company is a CLEC applying to rent space in an ILEC's central office, you must put your ACNA number on your application. If you don't, the ILEC will hold your application up. If you don't have an ACNA number, you need to get one from Telcordia.


  1. Additional Call Offering. An ISDN option that alerts a Terminal Adapter (TA) or ISDN-capable router that a second call is coming in over a given Bearer (B) channel. If the existing call is a data call, ACO provides the TA or router with the option of dropping the data call, in favor of the incoming voice call. In this scenario, it is assumed that the voice call takes priority over the data call.

  2. Alarm Cut Off. Feature that allows the manual silencing of the office audible alarm. ( Subsequent new alarm conditions might reactivate the audible alarm.)

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