Data Link & Error Control

Consider a network connecting two systems located 8000 kilometers apart. The bandwidth of the network is $500 \times 10^6$ bits per second. The propagation speed of the media is $4 \times 10^6$ meters per second. It is needed to design a Go-Back-N sliding window protocol for this network. The average packet size is $10^7$ bits. The network is to be used to its full capacity. Assume that processing delays at nodes are negligible. Then, the minimum size in bits of the sequence number field has to be _____.

A bit-stuffing based framing protocol uses an 8-bit delimiter pattern of 01111110. If the output bit-string after stuffing is 01111100101, then the input bit-string is