How do switches store and forward？

A store-and-forward switch is a network switch that operates by receiving an entire data frame before forwarding it to the destination. These switches are commonly used in Ethernet networks and are known for their ability to perform error checking and ensure data integrity before forwarding packets. Here is a detailed overview of store and forward switches:

Activity:

1. Frame reception: When a frame arrives at a store-and-forward switch, the switch buffers the entire frame in its memory before processing.

2. Error checking: The switch performs error checking on the received frames to ensure that it does not have errors such as CRC (Cyclic Redundancy Check) errors or framing errors.

3. Address lookup: Once the frame has been error-checked, the switch checks the destination MAC address in the frame header.

4. Forwarding decision: The switch performs a lookup in its MAC address table to determine the outgoing port for the destination MAC address.

5. Forwarding: If the target MAC address is found in the MAC address table, the switch forwards the frame out of the corresponding port. If the target MAC address is not found. The switch floods the frame out of all ports except the port that received the frame.

6. Transmission: After making the forwarding decision, the switch transmits the frame to the destination device.

Feature:

Error checking: Store-and-forward switches perform error checking on received frames to ensure data integrity before forwarding packets.

Address Learning: These switches maintain a MAC address table that associates MAC addresses with corresponding ports to optimize frame forwarding.

Conflict detection: Store and forward switches can detect conflicts on Ethernet segments to ensure reliable transmission of data.

Framebuffer: Store-and-forward switch buffers entire frames in memory before processing them, allowing for more accurate error checking and handling.

Advantage:

Data Integrity: By buffering and error checking the entire frame before forwarding, store and forward switches ensure data integrity and minimize the transmission of corrupted data.

Reliability: These switches are reliable and can help prevent network congestion and errors by forwarding only error-free frames.

Flexibility: Store-and-forward switches are suitable for a variety of network environments, including those with high error rates or variable frame sizes.

Limitation:

Latency: The store-and-forward process introduces additional latency compared to pass-through switches because frames must be fully received and checked for errors before they can be forwarded.

Bandwidth consumption: Store-and-forward switches consume more bandwidth than cut-through switches because they buffer the entire frame before forwarding it, which can lead to higher latency and lower throughput in congested networks.

Not suitable for real-time applications: The additional latency introduced by store-and-forward switches may not be suitable for real-time applications that require low and minimal latency, such as voice or video streaming.

In summary, a store-and-forward switch is a reliable and widely used network switch that ensures data integrity by error-checking the entire frame before forwarding it. Although they may introduce additional latency compared to pass-through switches, they are suitable for a variety of network environments and provide an effective solution for ensuring reliable data transmission in Ethernet networks.