RTFaxing: Internet Real-Time Faxing System

Internet faxing circumvents expensive international telephone toll charges in transcontinental fax exchanges by using the Internet as an intermediary medium to transport fax messages between senders and recipients. To make Internet faxing as successful as traditional faxing, it is necessary to support real-time delivery of fax messages over the Internet. However, existing fax transportation mechanisms such as Simple Mail Transfer Protocol (SMTP) and Transmission Control Protocol (TCP) are unable to provide such real-time support. Instead, real-time delivery will involve the transmission of packetised fax data through the packet switched network environment of the Internet with possible loss of data, thereby causing quality degradation. This paper proposes an Adaptive Control and Recovery (ACR) mechanism for supporting real-time fax communications over the Internet. The mechanism integrates the adaptive transmission control with dynamic recovery of lost fax packet data. Together with a buffering mechanism, the ACR mechanism has been implemented into RTFaxing, an Internet Real-Time Faxing System that was developed at the School of Applied Science, Nanyang Technological University, Singapore.