1. Calculate the overhead associated with the following protocol stack assuming transmission of 19,800 bits.
- Transport Header of 50 bits (max. data payload of 20,000 bits)
- Network Header of 550 bits (maximum data payload of 9,400 bits)
- Data Link Header of 20 bits and trailer of 20 bits (maximum data payload of 5,000 bits)
2. What would your answer be if the Transport layer was restricted to a maximum data payload of 10,000 bits? All other parameters stay the same as above.
1. At Transport Layer:
Since input data (19800 bits) is less than maximum data payload (20000 bits) of transport layer, entire data can fit in single transport packet (data unit).
Size of transport layer packet = (19800 bits data + 50 bits transport header) = 19850 bits
As output data from a layer serves as the input data for the next/adjacent layer, it will serve as input data for network layer.
At Network Layer:
Input data at network layer = 19850 bits
Since it is more than the maximum data payload (9400 bits) of network layer, it will be split into three network packet (data units) as follows.
550 bits network header + 9400 ...
Solution walks through the calculation in detail from transport layer to data link layer, showing the packets formation at different layers.