Header and Trailers

Question

Explain what are header and trailers and how they can be added and removed?

Answer 1

Each layer in sending machine adds its own information with the message it receives from layer just above it and passes forward the whole package to layer immediately below it. This information is then added in form of headers or trailers. Headers are added to message at the layers 6,5,4,3, and 2. A trailer is supplementary at the layer2. At the receiving machine, headers or trailers are attached to data unit at the corresponding sending layers are removed, and actions are suitable to that particular layer are taken.