Abstract:
Nowadays, the internet telephony is trendy replace the Ordinary PSTN, cause the benefit of cost, transmission efficiency and easy for OAM. Many of telecommunication manufacturers have already produced there product to support the internet telephony but the cost is still high and must be import from foreign country, since it is new technology and isnt a mass product. This thesis is development of low cost internet telephone prototype by using 805l family MCU AT89C51ED2, Ethernet controller RTL8019as, and PCM codec MCI14580 as the main hardware and the software development be composed of user interface part, Ethernet chip interface part, voice data control part, and protocol ICMP, ARP, IP, UDP, RTP, and SIP supported part, which are main protocol for basic internet telephone. Testing is done by using SIP User Agent program and another developed internet telephone operating as remote UA and SCS SIP Proxy program operating as server. The internet telephone prototype can create session, cancel session, reject session, and terminate session on both of direct connection mode and operating with sewer mode, which are the basic function of internet telephone. In the voice pan, internet telephone prototype can support PCM both of |1law and A-law, which is basic voice codec for internet telephone