Steady State Performance of Survivable Routing Procedures for Circuit-Switched Mixed-Media Networks.

Abstract : Three classes of new mixed-media routing procedures are presented for networks with both broadcast and point-to-point transmission media such as the Defense Switched Network. All procedures treat satellite and terrrestrial links separately and use common channel signaling to pass call setup information between switches. Mixed-media routing procedures use fixed routing tables and three different call processing rules. Adaptive-mixed-media routing procedures adapt routing tables when parts of the network are destroyed. Precedence flooding procedures route low-priority calls using mixed-media procedures and high-priority calls using flooding techniques. A steady state network analysis program was modified to evaluate the performance of (1) mixed-media routing with spill-forward control, (2) mixed-media routing with remote earth station querying and (3) adaptive mixed-media routing. These new routing procedures were compared to modified forward routing and primary path only routing using 20 and 40 node mixed-media networks under overload, with various patterns of offered traffic, and with different amounts and types of network damage. The new routing procedures studied, especially adaptive-mixed-media routing, substantially enhanced network performance after damage. These procedures did not reduce the average point-to-point blocking probability. They did, however, improve the service provided to the most poorly served group of users and they denied the possibility of call completion to the fewest users.