What is the main purpose of the 'Fragment Offset' field?

The 'Fragment Offset' field's primary purpose is to specify the order of the fragments in a fragmented packet. When a packet is too large to be transmitted in a single frame over a network, it is broken down into smaller segments, or fragments. Each fragment will contain a portion of the original packet's data, along with headers that include the Fragment Offset field.

This field provides crucial information that indicates the position of that fragment in the overall data stream. Specifically, it tells the receiving device how far into the original packet the data of that particular fragment starts. By using the offset, the receiving end can accurately reassemble the fragments back into their original order, ensuring that the data is reconstructed correctly and completely.

Without the Fragment Offset field, the device would have difficulty determining where each fragment belongs within the original data payload, potentially leading to data corruption or loss during reassembly. Hence, it plays an essential role in maintaining the integrity and order of transmitted data across a network.