Implementation of Voice over Internet Protocol (VoIP) using softphone applications based on Session Initiation Protocol (SIP)

Voice over Internet Protocol (VoIP) is a technology that can pass voice, video, and data over an Internet Protocol (IP) network. This study aims to implement VoIP using softphone applications based on Session Initiation Protocol (SIP) at the Said Na’um Education Foundation and to recognize both the voice quality resulting from the communication made using VoIP as well as the bandwidth required for voice quality that will be used appropriately. This study used Trixbox CE as the VoIP server while the client used two softphone applications installed on the client device for testing, 3CX for computers and Zoiper for the smartphone. The bandwidth system was set to 64, 128, and 256 Kbps and the voice quality was measured in terms of two tests, Quality of Service (QoS) and Mean Opinion Score (MOS). Quality was measured twice a day, in the morning and in the evening, and the results were compared to learn about its network traffic. The results of this study show that implementation of VoIP using softphone applications based on SIP works well in terms of the results of QoS and MOS, and a minimum bandwidth for the communication on VoIP was obtained at 64 Kbps.