An adapter for internet telephony system.

Ahmed Imad Ahmed Al-Nu'aimi
Dr. Manal J. Al-Kindi
Dr. Firas Abdullah Thweny

Abstract: Protocol (VoIP) phone that is interfaced to Personal Computer (PC), with an installed VoIP Softwares under Windows, like Net2Phone or Skype which uses Internet protocol to transport voice. The IP phone is a cThis thesis explains the design, implementation of a Voice over Internet ombination of software and electronic hardware. The user of an IP phone can carry out a conversation with another phone user just like an ordinary phone. There are two VoIP phones designed, one is wire VoIP phone, which is interfaced to PC via parallel port with an external interfacing card to the phone keypad, and the voice communication is done by connecting the PC sound card's speaker and microphone to the earphone and microphone of the phone handset respectively. The other phone is wireless VoIP phone which consists of handset and station, the data transmission, for pressed keys from handset keypad, is achieved by using the TWS-434 and RWS-434 modules with the a compatible Encoder HT-12E and Decoder HT-12D ICs, and the wireless voice transmission is accomplished by using a pair of ready made cordless headphones. The Software which manages the whole work, was written by Borland C++ Builder, and its operation is briefed by writing and reading data to and from the parallel port and finding the keys by key-code mapper then sending the keys to VoIP software (softphone) like Net2Phone and Skype and others.