A leaky-bucket-with-gate algorithm is proposed to control connection-setup congestion in telecommunication networks providing multimedia services, in place of the call-gapping algorithm used in telephone networks. Multimedia services may use more than one connection simultaneously, while standard telephone services use only one connection at a time. A set of connections used to construct a multimedia service is called a correlated connection group, and the setup requests of such a group form correlated request group. A correlated request group is assumed to be accepted into the network only when all the connection-setup requests for the group are accepted. In this paper, the proposed leaky-bucket-with-gate algorithm, a pure leaky-bucket algorithm, and a call-gapping algorithm are evaluated by simulating traffic with a mix of correlated and uncorrelated connection-setup requests, which models setup requests for video conferencing and telephone services. The simulation results show that the proposed algorithm accepts correlated request groups more efficiently than the pure leaky-bucket and call-gapping algorithms under the simulated traffic conditions, except when the interarrival time in a correlated request group is longer than the acceptance interval. We also present queueing analysis for determining the control parameters in the proposed algorithm. Implementation of this algorithm will facilitate the handling of both setup request traffic for correlated connection groups and for uncorrelated connections in multimedia networks.

Satellite-terrestrial (ST) networks, in which many nodes are interconnected by both satellite and terrestrial networks, can efficiently support multicast services. This is because satellite broadcasting is suitable for a large multicast group and a terrestrial network is suitable for a small multicast group. An ST network requires a multicast routing algorithm that can select the appropriate satellite and terrestrial routes. Conventional dynamic routing algorithms for terrestrial networks cannot construct an efficient multicast routing tree because they basically select a less-expensive route when a node is added. We have developed a dynamic routing algorithm, a virtual-cost-based algorithm, for ST networks that selects the route to use according to the multicast group size when a node is added to the group. Simulation showed that the proposed algorithm is advantageous when nodes are added to or removed from the multicast group during steady-state simulation.

Measuring traffic dynamics during intervals of a few seconds is important in the management of network performance. If the distribution of average traffic volume during a few seconds is measured, an administrator can manage the quality of the networks using the α percentile of the distribution. We propose a method of estimating the distribution of traffic volume during short intervals, such as a few seconds, by using only traffic information from the management information base (MIB) of routers or switches. This estimation method is based on traffic characteristics that are observed in traffic measurements in actual networks. It imposes little additional load on routers or switches and the computation time required to estimate the distribution is also short. Numerical examples using actual traffic data are also given.