Choosing the appropriate ISO layer for LAN interconnection

The authors discuss the technical ramifications involved in the choice between interconnecting local area networks with a layer 3 (ISO network layer) versus layer 2 (ISO data link layer) approach, that is, routers versus bridges. They consider the distinction between two layers and define routers and bridges. They then argue the case for each. They conclude that neither approach is better, in the sense that each has its appropriate problem space, and suggest a mixture of relays.<>