1)Explain why the performance of an Ethernet LAN decreases with an increase in the number of stations on the LAN, whereas it increases (at least initially) with the increase in the number of stations in a token-ring LAN? A)There are too many differences between Token Ring and Ethernet to list out here. You could read more about it from many useful search results for "ethernet vs. token ring." I'll point out a key difference and give you a source answering your question on performance.
Ethernet is based on CSMA/CD (carrier sense multiple access with collision detection), meaning multiple stations sense the carrier at the same time and send data when the carrier is free. However, there might be multiple stations sending a free carrier and send the data at the same time, causing "collision." Collision is the main factor affecting ethernet's performance. The more stations on the same LAN, the higher the collision rate, the lower the performance.
Token Ring, on the other hand, is based on a control/access given to the station owning the "token." Think of a token as the key to the media: whichever station has the token would be allowed to use the ring to send the data. So there would be no collision, just multiple stations competing for the same token. With not too many stations, the wait-for and claim of the token is very efficient (think of a video game with less players waiting to play it.) But if there are too many stations, most would just sit around and wait for the token, hence the flat-out of its performance. 2)What are the standards used for the various layers in an Ethernet-based network that is managed by the Internet management protocol? Assume that the Ethernet runs on 10 Mbps on an unshielded twisted-pair cable? A)The standards used for the various layers in an Ethernet-based network that is managed by the Internet management protocol are :