How does the geographical distance between the source and destination hosts on a network affect latency?
Answer
There is an affect, but it is in mere milliseconds and the distance would need to be quite large.
What are the benefits of packet switching?
Answer
Packet switching allows data to be sent more efficiently as it breaks data into smaller pieces that can be routed more quickly and if a packet doesn't arrive it can be tracked down quickly.
What should happen if a packet goes missing? Who (which layer) would handle this? What action would they have to take? And what additional information would be needed in the packet in order to handle it?
Answer
In some cases, it will be retransmitted at whatever level the packer was lost, but in others it may time out and give up, informing the sender of the problem.
As the packets are being transmitted through the network, can people other than the sender and receiver read the messages? What methods can we use to protect the message?
Answer
Yes, if someone wanted to access the packets they could, but this can be avoided by encrypting the data in the packets and occasionally tracking packets to ensure that others are not on your network.