Discuss the difficulties that one encounters when trying to build a bridge between the various Ethernet Token Ring and Token Bus LANs.?

Answer 1

Since there is no protocol known as Ethernet Token Ring I assume you are asking about the difference between Ethernet, Token Ring, and Token Bus usage. These are all different protocols, so connecting all three types of networks is not practical.

Token Bus networks were an early attempt to get mainframes to connect to terminals through a bus topology structure, utilizing a token for arbitration. Those networks typically ran at 4 Mbps. They were also subject to the same problem as a linear bus structure with Ethernet, which is a break in the cable would bring down the entire network.

A later version of Token ring uses a ring topology structure, where a failure in the network will not bring down the entire network. It still uses a token for station arbitration, but can ran at 16 Mbps. Newer versions of HSTR can run at 100 Mbps and there is a standard for a gigabit version.

Chances are you will need to bridge between Ethernet and Token Ring (not token bus). For that, you will need a bridge, router, or gateway that can convert between the protocols. In some cases the media is different as well, going from coaxial cable to unshielded twisted pair (UTP).

So the difficulties are in correctly converting the protocols between the two, connecting different media types together, and troubleshooting problems between the two networks.