The Design And Implementation Of Router Supports SIP Services Based On The Embedded System

With the hub of the Internet, Router has been widely used in various filed of industry. Meanwhile, Internet telephone has a considerable proportion on the market. Because of its flexibility, simplicity, scalab ility, SIP protocol has become one of the most important network protocols for IP phones. To design a router supporting SIP services, it is very convenient for the users to exchange information, where a router controls the connection of the network call. Therefore, the study on SIP services routers not only conforms to the needs of development of communication, but also has very important significance of implementation.The paper mainly researches on the designation and implementation of the e mbedded router supporting SIP services, including three parts as followed:Firstly, the basic function of the access type router is achieved in this paper. Assumed that multiple computers access to the internet through the router, the router can dynamically allocate network information if computers access to the network newly, recovers its network information and reassign to other computers if computers close, maintains and updates the routing table ensured that the data forwards correctly, can send and receive ARP request and response frame, and establishes the mapping relations between MAC addresses and IP addresses.Secondly, the function of the access type router is expanded in this paper. It can achieve the function of SIP registrar server and SIP proxy server, completes the registration of SIP phone clients, binds of address user name and so on. Moreover, tow SIP clients utilizing the routers can request, hold, and hang up call.Finally, the SIP router hardware architecture is designed in this paper. The MB9F618 development board is selected as the hardware platform, and the SIP router is designed and developed to establish the data interface between the Ethernet and SIP router and Ethernet frame filtering. Moreover, the testing platform is built to verify various functions of the SIP router.