Dimensioning of both-way circuits with overflows to separate routes

An approximated method for the dimensioning of both-way circuits with different overflow routes is presented using the equivalent random method. Numerical examples are used to illustrate the effects of the volume and distribution of traffic, of the number of circuits on the overflow, and of the direct routes on the call congestion. The relation between call congestion and the number of circuits on the overflow route is given, while keeping the total traffic volume and the number of direct circuits constant for different sets of traffic distribution. The both-way circuit is compared with the single direction operation using the same traffic profile and distribution and the identical number of direct and overflow circuits. At an acceptable call congestion level, the both-way circuit outperforms single direction operation, in addition to improving circuit utilization and flexibility