Digital Program-controlled Switches Embedded Network Interface System Design

High-speed IP-based networks are the latest innovation in the world of communications. The capacity of these networks is increasing at a prodigious rate. For many applications, the pricing of IP traffic has dropped below the tariffs associated with traditional TDM service. For this reason, significant effort is being expended on VoIP technologies. However,Inherent in all forms of VoIP is revolutionary change, whereby much of the existing telephony infrastructure will be replaced by novel IP-based mechanisms. Today's telephony technology, both those portions that VoIP aims to replace and those to which VoIP must interface, is extremely complex. Revolutionary implementations of its hundreds of features and thousands of variations cannot be expected to be developed in a short time frame.So we deside to adopt an alternative method of exploiting IP networks for telephony service, in unframed mode transparently transporting the TDM frame without any attempt at interpreting the data.This paper designs a network interface for digital stored-program-control exchange. This interface connects digital stored-program-control exchange from PCM, and connects Ethernet from RJ45. By tacking on the appropriate IP heade, this interface encapsulates each Tl or El frame in an IP packet. For this interface unframed mode transparently transports the TDM frame without any attempt at interpreting the data , it seamlessly interfaces to all existing PBX equipment. This method is evolutionary rather than revolutionary,and it farthestly protects inhere investment.So it is an ideal complement to VoIP.