What is protocol needed? For n devices in a network, what is the number of cable links required for a mesh, ring, bus, and star topology?

What is the protocol data unit (PDU) employed at each lower layer?

In Fig. 1, assume that the communication is between a process running at computer A with port address q and a process running at computer D with port address p. Show the contents of packets and frames at the network, data link, and transport layer for each hop.

How does information get passed from one layer to the next in the Internet model?

If the data link layer can detect errors between hops, why do you think we need another checking mechanism at the transport layer?

What is the difference between a port address, a logical address, and a physical address?