The Relative Effectiveness of Assigned and Shared Storage in a Switching System

This paper reports an exact quantitative evaluation of the relative effectiveness of line-assigned and line-shared buffer storage in a message switch, or of a circuit switch that holds blocked calls for later connection. It is well known that shared storage is more efficient than line storage in the sense that fewer message storage units are required to provide the same level of protection against message rejection. However, a unit of common storage may be considerably more expensive than a unit of line storage because of differences in the storage media itself and the need for additional control circuitry. Thus, an exact quantitative analysis of the relative effectiveness of line assigned and line-shared buffer storage can provide a basis for trade-off studies between the two types of storage.