ABSTRACT

Tan Suryani Sollu, The Distributed Queue Dual Bus (DQDB) Pre-implementation Plan at the Hasanuddin University Campus-Wide Area Network (supervised by Rhiza S. Sadjad and Suarga).

The Hasanuddin University Campus-Wide Area Network is currently utilizing a shielded twisted-pair (STP) network backbone connected by Symmetric High-data rate Digital Subscriber Line (SHDSL) modems. The network topology is a star connection of 7 (seven) clusters of Local Area Network throughout the campus, all of which are linked together to the Internet via multiple gateways. This existing condition is presented using Network Simulator 2.31 software package. The main simulation parameters are bandwidth, propagation delay, and the variation of queuing management at each link, derived from actual data monitored at the University Information Center (Pusat Informasi Universitas, PIU) Network Control Center (NCC).  Data are collected using Multi-Router Traffic Grapher (MRTG) and ping software facilities available at the NCC. 

The simulation has shown that there is a “bottleneck” situation at the link between node 7 and node 12 of the existing network, which is the link connecting all seven clusters to the Internet. This is indicated by the large number of packet-drops due to the collisions, increasing delay and very low throughput. 

An alternative of using a fiber-optic based network configuration is proposed in this research project. The proposed topology is a ring topology instead of the star. The Distributed Queue Dual Bus (DQDB) standard protocol IEEE 802.6 is proposed to be implemented in order to eliminate the “bottleneck” situation of the existing network.  A dual-ring single-mode fiber-optic transmission with the wavelength of 1310 nm is proposed to replace the STP network. The estimate total length of fiber-optic cable required is 2.64 km with the total loss of approximately 18 dB.