Store and forward is a telecommunications technique in which
informationInformation as a concept has many meanings, from everyday usage to technical settings. The concept of information is closely related to notions of constraint, communication, control, data, form, instruction, knowledge, meaning, mental stimulus, pattern, perception, and representation.The English...
is sent to an intermediate station where it is kept and sent at a later time to the final destination or to another intermediate station. The intermediate station, or
nodeIn communication networks, a node is a connection point, either a redistribution point or a communication endpoint . The definition of a node depends on the network and protocol layer referred to...
in a
networkingA computer network is a group of interconnected computers. Networks may be classified according to a wide variety of characteristics. This article provides a general overview of some types and categories and also presents the basic components of a network....
context, verifies the
integrityData integrity is a term used in computer science and telecommunications that can mean ensuring data is "whole" or complete, the condition in which data is identically maintained during any operation , the preservation of data for their intended use, or, relative to specified operations, the a...
of the message before forwarding it. In general, this technique is used in networks with intermittent connectivity, especially in the wilderness or environments requiring high mobility.
Store and forward is a telecommunications technique in which
informationInformation as a concept has many meanings, from everyday usage to technical settings. The concept of information is closely related to notions of constraint, communication, control, data, form, instruction, knowledge, meaning, mental stimulus, pattern, perception, and representation.The English...
is sent to an intermediate station where it is kept and sent at a later time to the final destination or to another intermediate station. The intermediate station, or
nodeIn communication networks, a node is a connection point, either a redistribution point or a communication endpoint . The definition of a node depends on the network and protocol layer referred to...
in a
networkingA computer network is a group of interconnected computers. Networks may be classified according to a wide variety of characteristics. This article provides a general overview of some types and categories and also presents the basic components of a network....
context, verifies the
integrityData integrity is a term used in computer science and telecommunications that can mean ensuring data is "whole" or complete, the condition in which data is identically maintained during any operation , the preservation of data for their intended use, or, relative to specified operations, the a...
of the message before forwarding it. In general, this technique is used in networks with intermittent connectivity, especially in the wilderness or environments requiring high mobility. It may also be preferable in situations when there are long delays in transmission and variable and high error rates, or if a direct, end-to-end connection is not available.
This technique originates the delay-tolerant networks. No real-time services are available for these kinds of networks.
Manually-operated relay
Store and forward networks predate the use of computers. Point-to-point teletype equipment was used to send messages which were stored at the receiving end on punched paper tape at a relay center. A human operator at the center removed the message tape from the receiving machine, read the addressing information, and then sent it toward its destination on appropriate outbound point-to-point teletype link. If the outbound link was in use, the operator placed the message in tape in a physical queue, usually consisting of a set of clips or hooks. A major relay center in the mid 1900s might have dozens of inbound and outbound teletypes, scores of operators, and thousands of messages in the queues during peak periods. Operators referred to these centers as "torn-
tape relayA tape relay is a method of retransmitting teletypewriter traffic from one channel to another, in which messages arriving on an incoming channel are recorded in the form of perforated tape, this punched tape then being either fed directly and automatically into an outgoing channel, or manually...
centers," a reference to removing the received message from the inbound teletype by tearing the paper tape to separate one message from the next. The U.S. military term for such a center was "Non-Automated Relay Center" (NARC).
Automatic relay
Plan 55-APlan 55-A was a store and forward message switching system developed by Western Union and used from 1948 to 1976. Western Union's own system handled telegrams, and a military version of the system was used by the U.S...
was an automatic, electromechanical store and forward message switching system. All message storage was performed by paper tape punches paired with paper tape readers, with a bin in between.
UUCP
Prior to the deployment of the
InternetThe Internet is a global system of interconnected computer networks that use the standardized Internet Protocol Suite to serve billions of users worldwide...
, computers were connected via a variety of point-to-point techniques, with many smaller computers using dial-up connections. The UUCP store-and-forward protocols allowed a message (typically e-mail) to move across the collection of computers and eventually reach its destination. Late in the 20th century, store and forward techniques evolved into
packet switchingPacket switching is a digital network communications method that groups all transmitted data, irrespective of content, type, or structure into suitably-sized blocks, called packets. The network over which packets are transmitted is a shared network which routes each packet independently from all...
which replaced it for most purposes.
See also
- Cut-through switching
In computer networking, cut-through switching is a switching method for packet switching systems, wherein the switch starts forwarding a frame before the whole frame has been received, normally as soon as the destination address is processed...
- Delay-tolerant networking
- Email forwarding
Email forwarding generically refers to the operation of re-sending an email message delivered to one email address on to a possibly different email address...
- FidoNet
FidoNet is a worldwide computer network that is used for communication between bulletin board systems. It was most popular in the early 1990s, prior to the introduction of easy and affordable access to the Internet...
- Fragment free
Fragment free is a switch forwarding method. Fragment free will hold the frame until the first 64 bytes are read from the source to detect a collision before forwarding. This is only useful if there is a chance of a collision on the source port - so a fully switched network may not benefit from...
- Hop-by-hop transport
Hop-by-hop transport is a principle of controlling the flow of data in a network. With hop-by-hop transport, chunks of data are forwarded from node to node in a store-and-forward manner....
- Internet fax
Internet fax uses the internet to receive and send faxes.Internet faxing is a general term which refers to sending a document facsimile using the Internet, rather than using only phone networks ....
- Network switch
A network switch is a computer networking device that connects network segments.The term commonly refers to a Network bridge that processes and routes data at the Data link layer of the OSI model...
- Packet radio
Packet radio is a form of packet switching technology used to transmit digital data via radio or wireless communications links. It uses the same concepts of data transmission via Datagram that are fundamental to communications via the Internet, as opposed to the older techniques used by dedicated...
- Stofor
Stofor, pronounced as in "Stow Four", is a store and forward message switching system designed by Fenwood Designs Ltd, UK in 1980.- Market and specification :...
- Store and forward delay
- Store-and-forward switching center
In telecommunication, a store-and-forward switching center is a message switching center in which a message is accepted from the originating user, i.e., sender, when it is offered, held in a physical storage, and forwarded to the destination user, i.e., receiver, in accordance with the priority...
- Wormhole routing
Wormhole flow control, also called Wormhole switching or Wormhole routing is a system of simple flow control in computer networking based on known fixed links. It is a subset of flow control methods called Flit-Buffer Flow Control. ....