Design and implementing VoIP network in the national defence university of Sri Lanka

General Sir John Kotelawala Defence University (KDU) is a one of the largest defence universities in the South Asian region. Internal telecommunication facility at KDU is an analog system, “Iwatsu Adix-E”, designed by Lanka Telecom Company in October 2010. Due to the limited number of connection slots on the hub and the high cost of end-devices to set up the telecommunication network, only 220 selected high priority users are fortunate to use the intercom facility. Only a few features are provided by the existing analog system; such as voice communication, calls on-hold, and call transfer. Since the KDU is a large organization at multiple geographical locations, a large number of calls are exchanged through the private branch exchange (PBX) per day. The two main problems in the existing analog system are; number of extensions cannot be increased and rewiring new tall buildings are very difficult and time consuming. Qualitative research techniques; interviews and observations, were used to collect data. The technical staff in the control room were interviewed to collect information on the existing system. The proposed system, a Voice over Internet Protocol (VoIP) would overcome the above mentioned problems in the existing system. This proposed system is a server-based-software-design, “AsteriskNow” software PBX Version 6.12.65-22. The TDM410p analog card is used to connect end-devices on a local area network (LAN). KDU has both a wired LAN and two (Wireless) Wi-Fi networks. KDU has its own Wi-Fi network provided by Lanka Education and Research Network (LERN) and the other by Dialog, the largest mobile operator in the Sri Lanka. Wi-Fi makes it is to connect the end devices to the server. But these wireless networks are not integrated and hence creating seamless connectivity issue. After implementing the VoIP system, there will be no additional cost (monetary) as service charges or monthly charges except a small maintenance cost and dat- charges. An authorized person or group of people can monitor all the conference and the data exchange through the system so the security of the system will be very high. No user can misuse the system in any manner. While the KDU is growing into multiple locations, the system can be easily expanded to provide the services with lower equipment cost, integration of voice and data applications, with lower bandwidth requirements. Proposed system with new features such as voicemail, call waiting, call conference and Instant Messaging (IM) will improve the existing telecommunication facilities at KDU.