A telephony system (10) for communication over a network includes a kernel space (110), a media express processor operating environment (120) for providing a set of software facilities for task synchronization, and a user space (130). The kernel space includes a board support package (111), a ucLinux module (112), a digital signal processor interface module (113), a transfer control protocol/Internet protocol (TCP/IP) stack (114) for performing TCP/IP, and a real-time transport protocol/real-time transport control protocol module (115). The user space includes a digital signal processor manager (132), an H.323/session initiation protocol (H.323/SIP) stack (133) for performing H.323 protocol or SIP, a system managing module (134), an event dispatcher (135), a line state machine (136), a call manager (137), a call logging module (138), and a directory module (139) for storing, editing, searching and removing contact information of users.