Voice over internet Protocol (VoIP) technologies are integral to trendy telecommunications attributable to their advanced options, flexibility, and economic advantages. web Service suppliers at first promoted these technologies by providing low value native and international occupation. At present, there's additionally a good deal of interest in mistreatment IP-based technologies to switch ancient little and enormous workplace telephone systems that use ancient PBX's (Private Branch eXchange). sadly, the massive majority of the rising VoIP based mostly workplace telephone systems have followed the centralized design of ancient public and personal telephone systems within which all the intelligence within the system is at the core, with quite expensive hardware and code parts and applicable redundancy for adequate levels of responsibility. The paper is meant to explain and analyze the feasibleness of the results of the VoIP system designed if enforced during a field network like national capital University telephone network. so the convergence strategy of an IP PABX system with the present wire telephone network has been mentioned. whereas taking this into thought, upgrading technique of the prevailing system using trendy network appliances has been delineate and at a similar time new configuration connecting this science network with the telephone network has been designed. This study entails the simulation and implementation of a VoIP telecom system mistreatment an IP PBX resolution. a replacement technology known as voice over internet Protocol (VoIP), or web telecom means your voice is carried over the IP network, otherwise referred to as the net. Voice, that is an analogue signal, is converted to digital knowledge, that is then disassembled and transmitted through net|the net} only to be reconverted back to an analogue signal on the opposite finish using an IP-PBX resolution that may be a UNIX base server that supports a interface web interface. This service may be properly managed and deployed over a network with less stress and expenses.