Store – and – Forward Packet Switching

In telecommunications, store-and-forward packet switching is a technique where data packets are stored in each intermediate node before being forwarded to the next node. The intermediate node verifies that the packet is error-free before transmitting, thus ensuring data integrity. The network layer typically operates using store-and-forward packet switching.

Working Principle

The source node delivers its packet to the nearest router. The packet is stored in the router until it has fully arrived and its checksum is verified for error detection. Once verified, the packet is transmitted to the next router. This process continues at each router until the packet reaches its destination.

In this example, host H1 sends a packet to host H2 through routers A, F, and D. Each router stores the complete packet, verifies its checksum using Cyclic Redundancy Check (CRC), and only forwards error-free packets to the next hop.

Advantages and Disadvantages

Advantages

• High data integrity − Erroneous packets are discarded at each router, ensuring reliable transmission

• Error detection − CRC verification at each hop prevents corrupted data propagation

• Network reliability − Bad or invalid packets are eliminated from the network

Disadvantages

• Increased latency − Each router must wait for the complete packet before forwarding

• Processing overhead − CRC computation adds delay at each intermediate node

• Cumulative delays − Multiple router delays make it unsuitable for time-critical applications

Conclusion

Store-and-forward packet switching provides reliable data transmission by verifying packet integrity at each router, but this reliability comes at the cost of increased latency. While excellent for applications requiring data accuracy, it may not be suitable for real-time communications that demand minimal delay.