Modem In The Access Server Software To Control And Realization Of Research

Near several years, along with the development of INTERNET, the network almost became a known to every household noun, and everyone hopes self can go up the net surfing, and this needs the network to provide the convenient and low cost service.The network access server (SP30NAS) of Xi'an DaTang Telecommunications Limited Company development is one kind of remote access equipment, located publicly the interface that meets the local area network of service of telephone net ( PSTN/ISDN ) with provides , with multitudinous dial user access local area networks . It can accomplish the long-range access and realizes virtual private network (VPN) and constructs INTERNET inside the enterprise building the network application. Author has participated in the research and development of this system, and took up the assignment that the drive control of first floor MODEM Chip Set in the NAM network access machine system (IAS) as well as the design and the realization of the network management of first floor. Design train of thought and implementation scheme expounded in this dissertation.The dissertation introduces development environment of pSOSystem operating system, concerned assignment and news queue mechanism. The performance and design principle of the important part of MODEM control module that the network access server (SP30NAS) met in the system (IAS) have been discussed. The hardware interface initialization, the receipt and transmitting of network data and management of MODEM channel have been realized to this module...