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A front end processor (FEP), or a communications processor, is a small-sized
computer which interfaces to the
host computer
A network host is a computer or other device connected to a computer network. A host may work as a server offering information resources, services, and applications to users or other hosts on the network. Hosts are assigned at least one network ...
a number of
network
Network, networking and networked may refer to:
Science and technology
* Network theory, the study of graphs as a representation of relations between discrete objects
* Network science, an academic field that studies complex networks
Mathematics ...
s, such as
SNA, or a number of
peripheral devices
A peripheral or peripheral device is an auxiliary device used to put information into and get information out of a computer. The term ''peripheral device'' refers to all hardware components that are attached to a computer and are controlled by the ...
, such as
terminals,
disk units,
printers
Printer may refer to:
Technology
* Printer (publishing), a person or a company
* Printer (computing), a hardware device
* Optical printer for motion picture films
People
* Nariman Printer ( fl. c. 1940), Indian journalist and activist
* Jam ...
and
tape units. Data is transferred between the host computer and the front end processor using a high-speed
parallel interface
In computing, a parallel port is a type of interface found on early computers (personal and otherwise) for connecting peripherals. The name refers to the way the data is sent; parallel ports send multiple bits of data at once (parallel c ...
. 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
The IBM 3705 Communications Controller is a simple computer which attaches to an IBM System/360 or System/370. Its purpose is to connect communication lines to the mainframe channel. It was a first communications controller of the popular IBM 3 ...
and the
Burroughs Data Communications Processor.
Sometimes FEP is synonymous with a communications controller, although the latter is not necessarily as flexible. Early communications controllers such as the
IBM 270x 270x is a generic name for a family of IBM non-programmable communications controllers used with System/360 and System/370 computers.
The family consisted of the following devices:
* IBM 2701 Data Adapter Unit
* IBM 2702 Transmission Control
* IB ...
series were
hard wired, but later units were programmable devices.
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 is the in situ collection of measurements or other data at remote points and their automatic transmission to receiving equipment (telecommunication) for monitoring. The word is derived from the Greek roots ''tele'', "remote", an ...
control, data collection, reduction of raw
sensor data, analysis of keyboard input, etc.
Front-end processes relates to the software interface between the user (
client
Client(s) or The Client may refer to:
* Client (business)
* Client (computing), hardware or software that accesses a remote service on another computer
* Customer or client, a recipient of goods or services in return for monetary or other valuabl ...
) and the application processes (
server
Server may refer to:
Computing
*Server (computing), a computer program or a device that provides functionality for other programs or devices, called clients
Role
* Waiting staff, those who work at a restaurant or a bar attending customers and su ...
) in the client/server architecture. The user enters input (data) into the front-end process where it is collected and processed in such a way that it conforms to what the receiving application (back end) on the server can accept and process. As an example, the user enters a URL into a
GUI
The GUI ( "UI" by itself is still usually pronounced . or ), graphical user interface, is a form of user interface that allows users to interact with electronic devices through graphical icons and audio indicator such as primary notation, inste ...
(front-end process) such as Microsoft Internet Explorer. The GUI then processes the URL in such a way that the user is able to reach or access the intended web pages on the web server (application server known as the “back end” process). Front-end processors or communications processors relates to efficient use of the host CPU by off-loading processing for peripheral control, as an example, to another device or controller.
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
IP 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
Quality of service (QoS) is the description or measurement of the overall performance of a service, such as a telephony or computer network, or a cloud computing service, particularly the performance seen by the users of the network. To quantitat ...
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.
See also
*
Interface Message Processor
The Interface Message Processor (IMP) was the packet switching node used to interconnect participant networks to the ARPANET from the late 1960s to 1989. It was the first generation of gateways, which are known today as routers. An IMP was a ...
References
External links
Front End Processors for Substations
{{DEFAULTSORT:Front End Processor
Embedded systems
Mainframe computers