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store and forward (SF)

Store and Forward(SF) is a switching technique, known from data packet switching, in which data pack ets or messages are forwarded over partial links from one network node to the next and are temporarily stored andchecked in these before being transmitted to the next node or the destination address.

The store-and-forward method operates on partial links and is therefore also referred to as the partial link method. Alternatively, there is the cut-through method, which has much shorter latency times. Both methods are used in the central components of switching systems, the routers or switches.

In the store-and-forward method, each incoming data packet is temporarily stored in the switch's buffer for a short time, filtered using various filters, and checked. This means that faulty data packets can be sorted out in advance and do not burden the transmission paths. Only then are the data packets forwarded to the next node or to the destination port. All header information is read and used for forwarding. This method has the advantage that forwarding is supported by filter mechanisms, error detection and error correction. This also means that the possible range of applications is much wider than for switching systems with cut-through procedures. Disadvantages are the higher latency in the switching network and the non-existent possibility of forming virtual networks.

If blocking occurs in the partial links, this is referred to as store-and-forward lockups. Store-and-forward lock ups can cause transmission links to be partially blocked, or total blockages in the form of deadlocks can occur. If switches work with the faster cut-through method and certain limit values are exceeded, the switches can switch to the error-free store-and-forward method.

Englisch: store and forward - SF
Updated at: 30.07.2019
#Words: 274
Links: service feature (IN) (SF), data packet, network node (NN), address (A), method
Translations: DE

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