Switched Multi-megabit Data Service (smds) Based On Star Network

Switched Multi-megabit Data Service (SMDS) is a high-speed, connectionless, packet switched, network service that operates over public data networks. It is intended to meet this emerging demand for high throughput and low delay between customers' LANs, computer systems, and advanced work stations. It can be implemented transparently over any type of network, but the IEEE P802.6 Distributed Queue Dual Bus (DQDB) was chosen as the basis for SMDS Interface Protocols at present.Although the technology of DQDB SMDS is already quite to be mature, we analyze DQDB agreement and find that DQDB SMDS has some insufficiencies because of DQDB agreement being imperfect and the request of quality of service being unceasingly enhanced in the integrated service network. Therefore, there is need for improvement in the SMDS network agreement. A new network system that would have better properties is presented in this paper—the double-star network.SMDS that is supported by the multi-star network (including the double-star network) can make accident information go through the central point in very short time so that obtains the idle exchange channel as soon as possible. The double-star network is regarded as operating under the condition of light load in this kind of situation. For evaluating the performance of the new system, the mathematical modeling of the system is studied under the condition of light load, which is requested in SMDS, for the first time in this paper. The simulation experiment shows that the double-star network could successfully exchange accident information and expand the system to serve for the synthesis service network when it replaces DQDB to implement SMDS. The result of this paper can give academic reference value to multi-star network applicable to SMDS.