Glossary

 

  A  -  B  -  C  -  D  -  E  -  F  -  G  -  H  -  I  -  L  -  M  -  O  -  P  -  R  -  S  -  T  -  U  -  W  -  X  -  Y  -  Z  
 

A

ADSL - Asymmetric Digital Subscriber Line. A form of DSL, a data communications technology that enables faster data transmission over copper telephone lines than a conventional voiceband modem can provide. It does this by utilizing frequencies that are not used by a voice telephone call. A splitter or micro filters allow a single telephone connection to be used for both ADSL service and voice calls at the same time. See DSL  Reference  

AFT - Advanced Flexible Telecommunications. A series of cards is based on a revolutionary technological concept by Sangoma's Chief Hardware Engineer, Michael Feldman, known as Advanced Flexible Telecommunications. The Sangoma series of AFT Cards take only a fraction of the resources of the competition to produce and operate, yet have quality in line high-end proprietary competitors. 

Analog - A signal that has a continuously and smoothly varying amplitude or frequency. Human speech, and everything else you hear, is in analog form, and early telephone systems were analog as well. Analog signals are often depicted as smooth sine waves, but voice and other signals are more complex than that, since they contain many frequencies. Reference  

API - Abbreviation of application program interface, a set of routines, protocols, and tools for building software applications. A good API makes it easier to develop a program by providing all the building blocks. A programmer then puts the blocks together. Most operating environments, such as MS-Windows, provide an API so that programmers can write applications consistent with the operating environment. Although APIs are designed for programmers, they are ultimately good for users because they guarantee that all programs using a common API will have similar interfaces. This makes it easier for users to learn new programs. Reference  

API Toolkit - See API  

Application - (Also applications software and end-user programs.) An application is a program or group of programs designed for end users. Figuratively speaking, applications software sits on top of systems software because it is unable to run without the operating system and system utilities. See Software  Reference  

Application Program Interface - See API  

Application Servers - A software engine that delivers applications to client computers or devices, typically through the Internet and using the HyperText Transfer Protocol. Application servers are distinguished from web servers by the extensive use of server-side dynamic content and frequent integration with database engines. Reference  

Asterisk - Asterisk is a complete IP PBX in software. It runs on a wide variety of operating systems including Linux, OpenBSD, FreeBSD and Sun Solaris and provides all of the features you would expect from a PBXs. Asterisk supports Voice over IP in many protocols, and can interoperate with almost all standards-based telephony equipment using relatively inexpensive hardware.

Asterisk is released as open source under the GNU General Public License (GPL), and it is available for download free of charge. Reference  

Asymmetric Digital Subscriber Line - See ADSL  

Asynchronous Circuits - An asynchronous circuit is a circuit in which the parts are largely autonomous. They are not governed by a clock circuit or global clock signal, but instead need only wait for the signals that indicate completion of instructions and operations. These signals are specified by simple data transfer protocols. This digital logic design is contrasted with a synchronous circuit which operates according to clock timing signals. Reference  

Asynchronous Transfer Mode - See ATM  

ATM - Asynchronous Transfer Mode. A cell relay, packet switching network and data link layer protocol which encodes data traffic into small (53 bytes; 48 bytes of data and 5 bytes of header information) fixed-sized cells. ATM provides data link layer services that run over Layer 1 links. This differs from other technologies based on packet-switched networks (such as the Internet Protocol or Ethernet), in which variable sized packets (known as frames when referencing Layer 2) are used. ATM is a connection-oriented technology, in which a logical connection is established between the two endpoints before the actual data exchange begins. Reference  

Auto Attendant - (Also Automated attendant, auto-attendant, autoattendant or AA.) A system that enables callers to be automatically transferred to a user's extension without the intervention of a receptionist. Reference  


 

B

bchan - B-channel or Bearer Channel. Refers to the ISDN channel in which the primary data or voice communication is carried. It has a bit rate of 64 kbit/s in full duplex. Reference  

BiSync - (BInary SYNChronous) A major category of synchronous communications protocols used in mainframe networks. Bisync communications require that both sending and receiving devices are synchronized before transmission of data is started. In the IBM world, bisync was superseded by SDLC. Contrast with asynchronous transmission. See SDLC  Reference  

Blade - Each blade is an independent server, with its own processors, memory, storage, network controllers, operating system and applications. The blade server simply slides into a bay in the chassis and plugs into a mid or backplane, sharing power, fans, floppy drives, switches, and ports with other blade servers. Not to be confused with Line Cards. See Line Cards  Reference  

BRI - In the Integrated Services Digital Network (ISDN), there are two levels of service: the Basic Rate Interface (BRI), intended for the home and small enterprise, and the Primary Rate Interface (PRI), for larger users. Both rates include a number of B-channels and a D-channel. Each B-channel carries data, voice, and other services. The D-channel carries control and signaling information.

The Basic Rate Interface consists of two 64 Kbps B-channels and one 16 Kbps D-channel. Thus, a Basic Rate Interface user can have up to 128 Kbps service. The Primary Rate Interface consists of 23 B-channels and one 64 Kpbs D-channel using a T-1 line or 30 B-channels and 1 D-channel using an E1 line. Thus, a Primary Rate Interface user on a T-1 line can have up to 1.544 Mbps service or up to 2.048 Mbps service on an E1 line. PRI uses the Q.931 protocol over the D-channel. Reference  


 

C

Call Centres - (Also Call Center.) A centralised office used for the purpose of receiving and transmitting a large volume of requests by telephone. Reference  

Call Progress Analysis - Call Progress Analysis (CPA), also called Call Progress Detection (CPD), is a generic term for signal processing algorithms that operate on audio during call setup. The goal of CPA is to determine the nature of the callee or the outcome of call setup to an external network (traditional or IP). Specifically, when a call or session is being established, the caller or initiator is interested in knowing if someone answered, if the line is busy, etc. When the caller is an automated application, such as an automated dialer or message broadcasting system, CPA algorithms are used to perform the classification automatically.

Modern CPA methods, such as those used by Sangoma's NetBorder Call Analyzer, in combination with automated outbound dialing applications, ensure fast and accurate automated call classification, which automatically translate in better efficiency of agents and higher quality customer interactions.

Traditional Call Progress Analysis implementations rely on simple rule-based algorithms which provide sub-optimal accuracy of speed of processing, leading to significant inefficiencies in operations and issues in meeting compliance from new government regulations.

Using statistical models based on Neural Networks to represent the potential outcomes of an outbound call attempt, companies can meet and exceed these regulations. This approach identifies much better the call patterns that represent call progress events and provides CPA results with far superior accuracy, speed and flexibility compared to traditional approaches. See Call Progress Detection  

Call Progress Detection  - Call Progress Analysis (CPA), also called Call Progress Detection (CPD), is a generic term for signal processing algorithms that operate on audio during call setup. The goal of CPA is to determine the nature of the callee or the outcome of call setup to an external network (traditional or IP). Specifically, when a call or session is being established, the caller or initiator is interested in knowing if someone answered, if the line is busy, etc. When the caller is an automated application, such as an automated dialer or message broadcasting system, CPA algorithms are used to perform the classification automatically.

Modern CPA methods, such as those used by Sangoma's NetBorder Call Analyzer, in combination with automated outbound dialing applications, ensure fast and accurate automated call classification, which automatically translate in better efficiency of agents and higher quality customer interactions.

Traditional Call Progress Analysis implementations rely on simple rule-based algorithms which provide sub-optimal accuracy of speed of processing, leading to significant inefficiencies in operations and issues in meeting compliance from new government regulations.

Using statistical models based on Neural Networks to represent the potential outcomes of an outbound call attempt, companies can meet and exceed these regulations. This approach identifies much better the call patterns that represent call progress events and provides CPA results with far superior accuracy, speed and flexibility compared to traditional approaches. See Call Progress Analysis  

CallWeaver - CallWeaver is a community-driven vendor-independent cross-platform open source PBX software project (formerly known as OpenPBX.org). It was originally derived from Asterisk. Now it supports analog and digital PSTN telephony, multi-protocol voice over IP telephony, fax, software-fax, T.38 fax over IP and many telephony applications such as IVR, conferencing and call centre queue management. Reference  

CHDLC - Cisco HDLC. (Also cHDLC.) An extension to the High-Level Data Link Control protocol created by Cisco Systems, Inc. cHDLC frames make use of an alternative framing structure to the standard ISO HDLC. One of the primary reasons for the creation of cHDLC was to address the HDLC protocol's inability to provide multiprotocol support. Thus, cHDLC frames contain a field for identifying the network protocol being encapsulated. Reference  

Clock Signal - A signal used to coordinate the actions of two or more circuits. A clock signal oscillates between a high and a low state, normally with a 50% duty cycle, and is usually in the form of a square wave. Circuits using the clock signal for synchronization may become active at either the rising edge, falling edge, or both edges of the clock cycle. Reference  

Color Ringback Tone - Instead of the familiar ring-tone, music, message or other personalized audio content is heard or seen by the calling party while they wait for the call to be answered. 

Crash-proof Firmware - Firmware that can be upgraded without risk of ruining the entire card in the event of a failure in the firmware upgrade process. A back up copy of the firmware is stored and can be reset by connecting two jumpers. 

Crossover Cable - Used when a Sangoma Card is not connected directly to the Telco, but to an external PBX system or channel bank, or to another computer in a back to back connection. (i.e. 614c) 


 

D

dchan - D-channel or Delta Channel. Refers to the ISDN channel that carries control and signalling information. The B-Channel carries the primary voice and data. Reference  

Digital Line Cards - See Line Cards  

DS0 - A DS0 (dee-ess-zero) is a 64-bit timeslot in a digital circuit. It is important because it represents the bandwidth necessary to carry a conversation over a phone line. This is the basic building block of digital telecom circuits, and all telecommunications throughout the world is based on this standard. 

DSL - Digital Subscriber Line. (Originally: digital subscriber loop.) DSL uses high frequency; regular telephone uses low frequency. Typically, upload speed is lower than download speed for Asymmetric Digital Subscriber Line (ADSL) and equal to download speed for Symmetric Digital Subscriber Line (SDSL). Reference  

DSP - Digital Signal Processor. A specialized microprocessor. 

DTMF - Dual Tone Multi Frequency. (Also Touchtone.) The signal to the phone company that you generate when you press an ordinary telephone's touch keys. Reference  


 

E

E1 - E1 is a wide-area digital transmission scheme (European) 2.048 Mbits/s, 31 channels, 64 Kbps each. E1 is transmitted as 32 timeslots and it permanently allocates capacity for a voice call for its entire duration. E1 circuits are very common in most telephone exchanges and are used to connect to medium and large companies, to remote exchanges and in many cases between exchanges. They are widely used in almost all countries outside the USA, Canada and Japan. 

Echo Cancellation - The process of removing echo from a voice communication in order to improve voice quality on a telephone call. In addition to improving subjective quality, this process increases the capacity achieved through silence suppression by preventing echo from traveling across a network. Reference  

EIA232 - (Also EIA-232.) A standard interface approved by the Electronic Industries Alliance (EIA) for connecting serial devices. In spite of challenges with this standard, EIA232 driver circuitry is highly tolerant of misconnections, and will usually survive a drive signal being connected to ground, or two drive signals connected to each other. Although EIA-232 is a common standard for serial communication, the EIA has recently defined successors to EIA-232 called RS-422 and RS-423. The new standards are backward compatible so that RS-232 devices can connect to an RS-422 port. Reference1  Reference2  

EPROM - Erasable Programmable Read-Only Memory, is a type of computer memory chip that retains its data when its power supply is switched off. 


 

F

Firmware - System software written onto read-only memory (ROM), it is a combination of software and hardware. ROMs, PROMs, and EPROMs are considered firmware if they have data or programs recorded on them. Reference  

Foreign Exchange Office - See FXO  

Foreign Exchange Station - See FXS  

Form Factor - A standard size and shape of computer subsystem. See U  

FPGA - A field-programmable gate array is a semiconductor device containing programmable logic components called logic blocks, and programmable interconnects. Logic blocks can be programmed to perform the function of basic logic gates such as AND, and XOR, or more complex combinational functions such as decoders or mathematical functions. Reference  

Frame Relay - A telecommunication service designed for cost-efficient data transmission for intermittent traffic between local area networks (LANs) and between end-points in a wide area network (WAN). Frame relay puts data in a variable-size unit called a frame. When an error is detected in a frame, it is simply dropped. (thrown away). The end points are responsible for detecting and retransmitting dropped frames. Frame relay requires a dedicated connection during the transmission period.

Frame relay complements and provides a mid-range service between ISDN, which offers bandwidth at 128 Kbps, and Asynchronous Transfer Mode (ATM), which operates in somewhat similar fashion to frame relay but at speeds from 155.520 Mbps or 622.080 Mbps. Reference  

FreeSwitch - FreeSwitch is an open source telephony platform designed to facilitate the creation of voice and chat driven products scaling from soft-phone up to a soft-switch. It can be used as a simple switching engine, a media gateway or a media server to host IVR applications using simple scripts or XML to control the callflow. Reference  

FXO - Analog FXO (Foreign Exchange Office) is the interface on a VoIP device for connecting to an analog PBX extension. 

FXS - Analog FXS (Foreign Exchange Station) is the interface on a VoIP device for connecting directly to phones, faxes, and CO ports on PBXs or key telephone systems. 


 

G

Gateway - (Also protocol converters.) Can operate at any layer of the OSI model. The job of a gateway is much more complex than that of a router or switch. Typically, a gateway must convert one protocol stack into another. Routers exemplify special cases of gateways. Reference  


 

H

Hardware Cards - Refers to PCI, PCI-x or PCI Express line cards. 


 

I

Interactive Voice Response - See IVR  

ITSP - An ITSP (Internet Telephony Service Provider) offers an Internet data service for making telephone calls using VoIP (Voice over IP) technology. Most ITSPs use SIP, H.323, or IAX (although H.323 use is declining) for transmitting telephone calls as IP data packets. Customers may use traditional telephones with an analog telephony adapter (ATA) providing RJ11 to Ethernet connection. Reference  

IVR - Interactive Voice Response. A phone technology that allows a computer to detect voice and touch tones using a normal phone call; can respond with pre-recorded or dynamically generated audio to further direct callers on how to proceed; can be used to control almost any function where the interface can be broken down into a series of simple menu choices. Once constructed IVR systems generally scale well to handle large call volumes. 


 

L

Latency - (1) In general, the period of time that one component in a system is spinning its wheels waiting for another component. Latency, therefore, is wasted time. For example, in accessing data on a disk, latency is defined as the time it takes to position the proper sector under the read/write head. (2) In networking, the amount of time it takes a packet to travel from source to destination. Together, latency and bandwidth define the speed and capacity of a network.
(3) In VoIP terminology, latency refers to a delay in packet delivery. VoIP latency is a service issue that is usually based on physical distance, hops, or voice to data conversion. Reference  

Line Cards - (Also Digital Line Card.) A modular electronic circuit on a printed circuit board, the electronic circuits on the card interfacing the telecommunication lines coming from the subscribers (such as copper wire or optical fibers) to the rest of the telecommunications access network. 

Line Signalling - Line signalling handles the state of the circuit at a low level. States, such as, 'on hook' and 'off hook' are examples of line signalling. 

Loopback Cable - is used to test your side of the network without the Telco. 


 

M

Media Server - A computer appliance, ranging from an enterprise class machine providing video on demand, to, more commonly, a small home computer storing various digital media. The only requirement for a media server is a method of storing media and a network connection with enough speed to allow access to that media. Reference  

Mediation Server - The Office Communications Server 2007 (OCS2007), Mediation Server, provides signaling and media translation between the OCS2007 VoIP infrastructure and a basic media gateway. On the Office Communications Server side, Mediation Server listens on a single mutual TLS transport address. On the gateway side, Mediation Server listens on a single TCP or TLS transport address. The main functions of the Mediation Server are:

Encrypting and decrypting SRTP (Secure Real-time Transport Protocol) on the Office Communications Server side.
Translating SIP over TCP to SIP over mutual TLS.
Translating media streams between Office Communications Server and the media gateway.
Connecting clients that are outside the network to internal ICE (Interactive Connectivity Establishment) components, which enable media traversal of NAT and firewalls.
Acting as an intermediary for call flows that a gateway does not support, such as calls from remote workers on an Enterprise Voice client.
 

MF Tones - Similar to DTMF, Multi Frequency tones are used to pass signalling information between telecommunications switches. This is considered an older style of signalling, as nowadays, this sort of information is passed digitally, however MF remains in use throughout the world. 

MFC - Multi Frequency Compelled. This is a mechanism whereby audio tones are sent down telecom circuits in order to convey signalling information (Caller ID, for example). 

MFCR2 - (Also MFC/R2.) A protocol originally used to provide register to register signaling over analogue copper wiring at a higher speed than had been possible with pulse dialing. Monitoring for the end of the call is handled by the line signals alone. MFC/R2 channels may be configured for only incoming calls or only outgoing calls. However, most national variants permit each channel to handle both incoming and outgoing calls. The protocol does not avoid collisions, but can gracefully detect a collision and reallocate a call to another channel. Reference  


 

O

Octopus cable - A cable that is spliced into several branches. There is one connector on one end and multiple connectors on the other. 

Open Systems Interconnection - (Also OSI Seven Layer Model.) Layered, abstract description for communications and computer network protocol design. From top to bottom, the OSI Model consists of the Application, Presentation, Session, Transport, Network, Data Link, and Physical layers. A layer is a collection of related functions that provides services to the layer above it and receives service from the layer below it. For example, a layer that provides error-free communications across a network provides the path needed by applications above it, while it calls the next lower layer to send and receive packets that make up the contents of the path. Reference  

OSI - See Open Systems Interconnection  


 

P

Packet - A unit of data that is routed between an origin and a destination on the Internet or any other packet-switched network. Depending on the type of network, packets may be referred to as a frame, block, cell, or segment.
Each packet carries the information that will help it get to its destination, e.g., the sender's IP address, the intended receiver's IP address, something that tells the network how many packets message has been broken into and the number of this particular packet. Reference1  Reference2  

PBX - is a private telephone network used within an enterprise. Users of the PBX share a certain number of outside lines for making telephone calls external to the PBX.

Most medium-sized and larger companies use a PBX because it's much less expensive than connecting an external telephone line to every telephone in the organization. In addition, it's easier to call someone within a PBX because the number you need to dial is typically just 3 or 4 digits.

PBXs are also referred to as PABX (Private Automatic Branch Exchange) and EPABX (Electronic Private Automatic Branch Exchange). Reference1  Reference2  

PCI - Peripheral Component Interconnect. (Also PCI Standard.) Specifies a computer bus for attaching peripheral devices to a computer motherboard. The bus is being succeeded by PCI Express, which offers much higher bandwidth. Reference  

PCI Express - Peripheral Component Interconnect Express. A computer expansion card interface format. Unlike previous PC expansion interfaces, (Like PCI or PCI-x) rather than being a bus it is structured around point-to-point serial links called lanes. Officially abbreviated as PCI-E or PCIe. Reference  

PCI-x - Peripheral Component Interconnect Extended. A computer bus and expansion card standard designed to supersede PCI. It is a double-wide version of PCI, running at up to four times the clock speed, but is otherwise similar in electrical implementation and uses the same protocol. Superseded by the similar sounding PCI Express. Reference  

Pinout - A term used in electronics to describe how an electrical connector is wired. An electrical connector typically consists of several electrical contacts or pins that can be used to carry electrical power or signals. Due to the wide variety of applications and manufacturers, a wide selection of electrical connectors exists with different types and numbers of contacts or pins. The pinout of a connector identifies each individual pin, which is critical when creating cable assemblies and adapters. Proper identification of pins and wires ensures that the signals and power are transmitted across cables and connectors. Reference  

Portsplitter cables - Sangoma's port-splitter cable is a Y-Cable enables the space of one physical port to support two ports. 

POTS - See PSTN  

PPP - Point-to-Point Protocol. A data link protocol commonly used to establish a direct connection between two nodes over serial cable, phone line, trunk line, cellular telephone, specialized radio links, or fiber optic links. Two common encapsulated forms of PPP, Point-to-Point Protocol over Ethernet (PPPoE) or Point-to-Point Protocol over ATM (PPPoA), are used in a similar role with Digital Subscriber Line (DSL) Internet service. PPP is commonly used to act as a data link layer protocol for connection over synchronous and asynchronous circuits. Reference  

PPPoA - Point-to-Point Protocol (PPP) over ATM, is a network protocol for encapsulating PPP frames in ATM. It offers standard PPP features such as authentication, encryption, and compression. Reference  

PPPoE - PPPoE, Point-to-Point Protocol over Ethernet, is a network protocol for encapsulating Point-to-Point Protocol (PPP) frames inside Ethernet frames. Reference  

PRI - Primary Rate Interface. In the Integrated Services Digital Network (ISDN), there are two levels of service: the Basic Rate Interface (BRI), intended for the home and small enterprise, and the Primary Rate Interface (PRI), for larger users. Both rates include a number of B-channels and a D-channel. Each B-channel carries data, voice, and other services. The D-channel carries control and signaling information.
The Primary Rate Interface channels are carried on a T-carrier system line (in the U.S., Canada, and Japan) or an E-carrier line (in other countries) and are typically used by medium to large enterprises. The 23 (or 30) B-channels can be used flexibly and reassigned when necessary to meet special needs such as videoconferences. The Primary Rate user is hooked up directly to the telephone company central office. Reference  

PROM - Programmable Read Only Memory. A programmable read-only memory (PROM) or field programmable read-only memory (FPROM) is a form of digital memory where the setting of each bit is locked by a fuse or antifuse. Such PROMs are used to store programs permanently. See Firmware  

Protocols - The rules and conventions for communication between computing endpoints. In its simplest form, a protocol can be defined as the rules governing the syntax, semantics, and synchronization of communication. Protocols may be implemented by hardware, software, or a combination of the two. At the lowest level, a protocol defines the behavior of a hardware connection. Protocols for computer networking all generally use packet switching techniques to send and receive messages in the form of packets. Reference1  Reference2  

PSTN - Public Switched Telephone Network. Refers to the international telephone system based on copper wires carrying analog voice data. This is in contrast to newer telephone networks base on digital technologies, such as ISDN and FDDI.

Telephone service carried by the PSTN is often called plain old telephone service (POTS). Reference  

Public Switched Telephone Network - See PSTN  


 

R

R2 - R2 is the name given to two broad protocol groups: R2 line signalling and R2 register signalling. R2 signalling refers to a vast number of variants of R2 which all resemble each other to varying degrees. Reference  

RBS - See Robbed Bit Signalling  

Register Signalling - Register signalling handles the rest of the signalling information; the details of the call. Examples of register signalling are ANI (who is calling) and DNIS (what number was dialed). 

Remora cards - Sangoma's trademark daughtercard design that is populated by the circuitry to connect to the PSTN. 

RJ45 connectors - The RJ-45 connector is commonly used for network cabling and for telephony applications. Reference  

Robbed Bit Signalling - A signaling method in a T1 circuit that uses bits from each of the 24 DS-0 channels. When channels carry switched voice traffic, each channel bank must be able to alert the other when a call is being placed on that channel. T-carrier systems grab one bit from each sixth voice sample to do this, which works out to 1,333 bps from the 64 Kbps channel. When a channel is seized from one end, the signaling bit is changed from 0 to 1 to alert the far end. The other signaling option is an ISDN PRI circuit where all signals travel in a separate, shared D channel carried in the 24th time slot. Reference  

ROM - See Firmware  

RPM - RPM Package Manager. (Originally Red Hat Package Manager.) A package management system. The name RPM refers to two things: a software package file format, and software packaged in this format. RPM was intended primarily for Linux distributions; the file format RPM is the baseline package format of the Linux Standard Base. 

RS232 - Recommended Standard RS-232. (Also RS232, EIA232, EIA-232.) Standard was renamed the EIA232 Standard in the early 1990s. See EIA232  

rx/tx - Receive (rx) and transmit (tx). 


 

S

SDLC - Synchronous Data Link Control. A protocol developed by IBM for use in SNA environments. Unlike Bi-Sync it separates the link control functions from the character set and data content. SDLC was the first link-layer protocol based on synchronous, bit-oriented operation. See SNA  Reference1  Reference2  

Serial Interface - A serial interface is a device that enables the serial exchange of data, one bit at a time, between a microprocessor and peripherals, such as printers, external drives, scanners, or mice. It also enables serial communications with another microprocessor or with an external network. Reference  

Session Border Controller - Session Border Controller (SBC) control the signalling (SIP, H.323, MGCP) and the Media (RTP voice and video) between calling and called parties in a VoIP call. SBCs allow to control the kinds of calls that can be placed through the networks on which they reside, fix or change protocols and protocol syntax to achieve interoperability, and also overcome some of the problems that firewalls and NAT cause for VoIP calls. 

SNA - SYSTEMS NETWORK ARCHITECTURE. SNA layers are not identical to the OSI layers and are not compatible or interoperable. Reference  

Socket API - A socket is an interface between an application process or thread (child process) and the TCP/IP protocol stack provided by the operational system. Reference  

Software - Software can be divided into two general classes: systems software and applications software. Systems software consists of low-level programs that interact with the computer at a very basic level. This includes operating systems, compilers, and utilities for managing computer resources. See Application  Reference  

Software Drivers and Utilities - Software drivers are computer programs that allow higher-level programs to interact with a computer hardware device. Reference  

SS7 - (Also CCS7 (Common Channel Signaling System 7), C7, Number 7, and CCIS7 (Common Channel Interoffice Signaling 7).) A standard for control signaling in the PSTN (Public Switched Telephone Network.) SS7 signaling is done out-of-band, meaning that SS7 signaling messages are transported over a separate data connection. This represents a significant security improvement over earlier systems which used in-band signaling. Reference  

Synchronous Circuits - A digital circuit in which the parts are synchronized by a clock signal. Reference  


 

T

T1 - T1 is a 1.544 Mbps, point-to-point, dedicated digital circuit provided by telephne companies consisting of 24 channels. T1 is a high speed digital network developed by AT&T in 1957 and implemented in the early 1960s to support long-haul pulse code modulation (PCM) voice transmission. The primary innovation of T1 was to introduce digitized voice and to create a network fully capable of digitally representing what was up until then, a fully analog telephone system. Reference  

TCP/IP - (Also TCP/IP protocol suite and Internet Protocol Suite.) Named after the Transmission Control Protocol (TCP) and the Internet Protocol (IP), the first two networking protocols defined. Can be viewed as a set of layers, each solving a set of problems involving the transmission of data, and providing a well-defined service to the upper layer protocols based on using services from some lower layers. The TCP/IP reference model consists of four layers. From lowest to highest, these are the link layer, the network layer, the transport layer, and the application layer. Reference  

TDM - Time-Division Multiplexing. A type of digital or analog multiplexing in which two or more signals or bit streams are transferred simultaneously as sub-channels in one communication channel, but physically are taking turns on the channel. The time domain is divided into several recurrent timeslots of fixed length, one for each sub-channel. Reference  

Telco - 'Telco' or 'TELCO' is a generic term for telephone companies. 

Telephony - Telephony encompasses the general use of equipment to provide voice communication over distances, specifically by connecting telephones to each other. Reference  

Time-Division Multiplexing - See TDM  

Trunk - In telecommunications, a trunk is one of:
* In a communications network, a single transmission channel between two points, which are the switching centers or nodes or both.
* A circuit between telephone switchboards or other switching equipment, as distinguished from local loop circuits which extend from telephone exchange switching equipment to individual telephones or information origination/termination equipment. See Trunk Line  Reference  

Trunk line - 1. A direct line between two telephone switchboards.
2. The main line of a communications or transportation system. See Trunk  Reference  


 

U

U - Unit. The 1U, 2U, 3U, 4U, 5U, 6U and 7U are all different sized rackmount servers; the U following the number is short for unit. The number indicates the size of the rackmount, 1U being the smallest rackmount and 7U being the biggest rackmount. Although the Width and Height of a rackmount may be standard, the depth of a rackmount may change. Reference  


 

W

WAN - Wide Area Network. A computer network that covers a broad area (i.e., any network whose communications links cross metropolitan, regional, or national boundaries. The largest and most well-known example of a WAN is the Internet. However, many WANs are built for one particular organization and are private. Reference  

Wanpipe or Wanpipe Router - Wanpipe® is a Sangoma Product that allows your server to do the WAN routing, with no separate router; no separate DSU/CSU, no nest of cables or extra power supplies. It also includes a suite of diagnostic tools. 


 

X

X.25 - A protocol that allows computers on different public networks to communicate through an intermediary computer at the network layer level. Corresponds closely to the data-link and physical-layer protocols defined in the Open Systems Interconnection (OSI) communication model. Reference  


 

Y

Y-Cable - A Y-cable or Y cable is a self describing name of a type of cable containing three ends of which one is a common end that in turn leads to a split into the remaining two ends. When looked upon, a Y-cable can resemble the Latin letter Y. Y-cables are typically, but not necessarily, short (less than 12 inches), and often the ends connect to other cables. Uses may be as simple as splitting one audio or video channel into two, to more complex uses such as splicing signals from a high density computer connector to its appropriate peripheral . Y-shaped mains leads are also becoming popular in some countries, enabling 2 appliances to run from one mains plug. See Portsplitter cables  Reference  

YATE - YATE (Yet Another Telephony Engine) is a next-generation telephony engine; while currently focused on Voice over Internet Protocol (VoIP) and Public Switched Telephone Network (PSTN), its power lies in its ability to be easily extended. Voice, video, data and instant messaging can all be unified under YATE's flexible routing engine, maximizing communications efficiency and minimizing infrastructure costs for businesses. Reference  


 

Z

Zaptel - Zaptel refers to Jim Dixon's open computer telephony hardware driver API.