1. Answer the following questions about layered protocol models.

   1. Consider the 5-layer Internet Protocol Stack. The layers from top to bottom are application, transport, network, link, and physical. All layers use headers and the transport layer also uses a trailer. Sketch a packet showing headers and trailers.

   2. Assume another protocol stack that uses variable length packets of maximum payload size 250 bytes. In addition to the payload, there are 20 bytes of network-layer header, 20 bytes of transport-layer header, and 10 bytes of trailer in each packet. For a 650-byte message, what is the overhead (in %) for this protocol?