A VoIP Softphone on a Bare PC

We describe the architecture, design, and implementation of a VoIP softphone that runs on a bare Intel-386 (or above) based PC. We compare the performance of bare PC and WinRTP softphones on the Internet by determining call quality and measuring the values of jitter, delay, and packet loss. We also conduct experiments on a LAN to test the limits of the bare PC softphone under heavy load conditions, and investigate the use of voice packets with Ethernet headers only (Voice over Ethernet) to minimize voice bandwidth. The results indicate that a bare PC softphone on the Internet is associated with less jitter than the WinRTP softphone. It is also able to sustain a heavier load on a LAN than the WinRTP softphone while maintaining acceptable call quality. We obtained excellent to good call quality with bare PC softphones running Voice over Ethernet.