Front end processor
Encyclopedia
A front end processor or a communications processor, is a small-sized computer
which interfaces to the host computer a number of network
s, such as SNA, or a number of peripheral devices, such as terminals
, disk units
, printers
and tape units
. Data is transferred between the host computer and the front end processor using a high-speed parallel interface. The front end processor communicates with peripheral devices using slower serial interfaces, usually also through communication networks. The purpose is to off-load from the host computer the work of managing the peripheral devices, transmitting and receiving messages, packet assembly and disassembly, error detection, and error correction. Two examples are the IBM 3705 Communications Controller
and the Burroughs Data Communications Processor.
Sometimes FEP is synonymous with a communications controller, although the latter is usually not as flexible.
Front end processor is also used in a more general sense in asymmetric multi-processor systems. The FEP is a processing device (usually a computer) which is closer to the input source than is the main processor. It performs some task such as telemetry
control, data collection, reduction of raw sensor
data, analysis of keyboard input, etc.
as a universal protocol, it is often assumed that there is no longer any need for FEPs , which traditionally handled SNA traffic. This may be true where FEPs provide only straight connectivity (and assuming IP address never changes). However, FEPs also perform other vital functions, that are closely linked to transaction applications, including message and transaction switching, multiplexing
, transaction security, Quality of Service
guarantors, and end-to-end transaction management and reporting. The need for these functions is especially important in mission critical transaction environments such as banking, government, point-of-sale, security, and health care applications. In these environments, FEP functionality is more necessary than ever before.
Although the IBM Corporation withdrew its 3745/3746 Communications Front End Processors from marketing in 2003, the company continues to maintain the estimated 20,000 installed front end processors. IBM also provides microcode enhancement features. Smaller companies have filled the void created by IBM's action, providing machines, features, parts and services worldwide.
Computer
A computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations. The particular sequence of operations can be changed readily, allowing the computer to solve more than one kind of problem...
which interfaces to the host computer a number of network
Computer network
A computer network, often simply referred to as a network, is a collection of hardware components and computers interconnected by communication channels that allow sharing of resources and information....
s, such as SNA, or a number of peripheral devices, such as terminals
Computer terminal
A computer terminal is an electronic or electromechanical hardware device that is used for entering data into, and displaying data from, a computer or a computing system...
, disk units
Hard disk
A hard disk drive is a non-volatile, random access digital magnetic data storage device. It features rotating rigid platters on a motor-driven spindle within a protective enclosure. Data is magnetically read from and written to the platter by read/write heads that float on a film of air above the...
, printers
Computer printer
In computing, a printer is a peripheral which produces a text or graphics of documents stored in electronic form, usually on physical print media such as paper or transparencies. Many printers are primarily used as local peripherals, and are attached by a printer cable or, in most new printers, a...
and tape units
Tape drive
A tape drive is a data storage device that reads and performs digital recording, writes data on a magnetic tape. Magnetic tape data storage is typically used for offline, archival data storage. Tape media generally has a favorable unit cost and long archival stability.A tape drive provides...
. Data is transferred between the host computer and the front end processor using a high-speed parallel interface. The front end processor communicates with peripheral devices using slower serial interfaces, usually also through communication networks. The purpose is to off-load from the host computer the work of managing the peripheral devices, transmitting and receiving messages, packet assembly and disassembly, error detection, and error correction. Two examples are the IBM 3705 Communications Controller
IBM 3705 Communications Controller
The IBM 3705 Communications Controller was a simple computer which attached to a IBM System/360 or System/370. Its purpose was to connect communication lines to the mainframe channel. It was a first communications controller of the popular IBM 37xx series. It was announced in March 1972...
and the Burroughs Data Communications Processor.
Sometimes FEP is synonymous with a communications controller, although the latter is usually not as flexible.
Front end processor is also used in a more general sense in asymmetric multi-processor systems. The FEP is a processing device (usually a computer) which is closer to the input source than is the main processor. It performs some task such as telemetry
Telemetry
Telemetry is a technology that allows measurements to be made at a distance, usually via radio wave transmission and reception of the information. The word is derived from Greek roots: tele = remote, and metron = measure...
control, data collection, reduction of raw sensor
Sensor
A sensor is a device that measures a physical quantity and converts it into a signal which can be read by an observer or by an instrument. For example, a mercury-in-glass thermometer converts the measured temperature into expansion and contraction of a liquid which can be read on a calibrated...
data, analysis of keyboard input, etc.
Communications FEPs in IP era
FEPs are responsible for linking client applications and their associated networks to host computer based applications. With the advent of the Internet and of IPInternet Protocol
The Internet Protocol is the principal communications protocol used for relaying datagrams across an internetwork using the Internet Protocol Suite...
as a universal protocol, it is often assumed that there is no longer any need for FEPs , which traditionally handled SNA traffic. This may be true where FEPs provide only straight connectivity (and assuming IP address never changes). However, FEPs also perform other vital functions, that are closely linked to transaction applications, including message and transaction switching, multiplexing
Multiplexing
The multiplexed signal is transmitted over a communication channel, which may be a physical transmission medium. The multiplexing divides the capacity of the low-level communication channel into several higher-level logical channels, one for each message signal or data stream to be transferred...
, transaction security, Quality of Service
Quality of service
The quality of service refers to several related aspects of telephony and computer networks that allow the transport of traffic with special requirements...
guarantors, and end-to-end transaction management and reporting. The need for these functions is especially important in mission critical transaction environments such as banking, government, point-of-sale, security, and health care applications. In these environments, FEP functionality is more necessary than ever before.
Although the IBM Corporation withdrew its 3745/3746 Communications Front End Processors from marketing in 2003, the company continues to maintain the estimated 20,000 installed front end processors. IBM also provides microcode enhancement features. Smaller companies have filled the void created by IBM's action, providing machines, features, parts and services worldwide.