Collisions and Connectivity:

a$)$ Why is full duplex mode better than half duplex mode?

b$)$ If two devices with different speed and duplex modes are connected, and only one is capable of auto$-$negotiation, what happens?

Ethernet Frames:

c$)$ The IEEE $802\mathrm{.}3$ standard sets a minimum frame size. Suppose that a frame smaller than that size is caused by collision. What happens to it$?$

d$)$ What is the purpose of the preamble?

e$)$ What type of error checking is used?