Computer networks

1. Can 1-dimensional parity absolutely detect any odd number of errors? Justify your answer. Can 2-dimensional parity absolutely detect 2-bit errors? Justify your answer. Can 2-dimensional parity absolutely detect 4 bit errors? Justify your answer.

2. Suppose that a node would like to send 10011011. The polynomial used for the generator is x³+x+1. What will be the bit stream sent by the node?

3. In CSMA/CD, after the 6^th collision, what is the probability that a node chooses K=6? Suppose that the length of each slot is the time to transmit 512 bits. For K=6, a node needs to wait for 6 time slots. How many second is that waiting time on a 10Mbps Ethernet?