MANAGEMENT OF VOICE TRANSMISSION ON ETHERNET

Abstract

The aim of this project is to develop a package to manage the telephone functions on the network. A Client-Server model is used for the software. OS/2 version 1.1 is used for the Server system, while all the client systems are DOS workstations (versions 3.3 and 4.0). LAN Manager version 1.1 is the networking software used. The interface between the handset and the PC is a voice card built in the Communication laboratory of this University. 'The Inter Process Communication (IPC) mechanisms offered by the LAN Manager are fully exploited to establish communication between Server and Client processes and between two clients. Facilities to make a call, answer a call and end a call are provided to the client. The Server processes such requests and helps the clients to establish communication with each other. Once this is achieved the Server process stores the clients names and removes itself from the scene of conversation. The clients again establish communication with the Server at the end of a call. This is to inform the Server that they are now available for any incoming call. An additional service is offered by the Server. If a request comes in for a callee who is already engaged in conversation then the caller is offered the choice of queueing his name against that of the callee. At the end of the conversation Server notifies the callee of the queued call. To establish connection with the caller the callee has to proceed as in a normal MakeCall request. The Server process besides handling the requests from the clients, is designed to dynamically vary the channels made available to users for conversations. This was further verified by having six DOS stations run the client process and communicate with the Server system. Requests were automated at various call arrival rates. The results obtained demonstrate the successful working of the package as a whole. At every stage of communication, all the possible occurences of failure have been considered and dealt with appropriately. Care has been taken to see that any type of failure at the Client end does not tie up the Server process.