Which layer performs segmentation into data units around 1500 bytes and reassembles them at the destination?

Which layer performs segmentation into data units around 1500 bytes and reassembles them at the destination?

• A. Layer 4 Transport
• B. Layer 3 Network
• C. Layer 2 Data Link
• D. Layer 1 Physical

Answer: (A)

Segmentation and reassembly of data for end-to-end delivery happens at the Transport layer. This layer takes the stream of data from an application and divides it into manageable pieces called segments. On Ethernet-like networks, those segments are sized to fit the typical MTU, often around 1500 bytes, to minimize fragmentation in the network. When the data arrives at the destination, the Transport layer reassembles the incoming segments back into the original data stream so the application can process it as a continuous flow. This end-to-end handling is what lets reliable transport protocols, like TCP, ensure data arrives correctly and in order.

Segmentation and reassembly of data for end-to-end delivery happens at the Transport layer. This layer takes the stream of data from an application and divides it into manageable pieces called segments. On Ethernet-like networks, those segments are sized to fit the typical MTU, often around 1500 bytes, to minimize fragmentation in the network. When the data arrives at the destination, the Transport layer reassembles the incoming segments back into the original data stream so the application can process it as a continuous flow. This end-to-end handling is what lets reliable transport protocols, like TCP, ensure data arrives correctly and in order.