数字程控交换机嵌入式网络接口系统的设计

【作者】 朱晓舒；

【导师】 刘国锦；

【作者基本信息】 南京师范大学 ， 物理电子学， 2003， 硕士

【摘要】 基于IP的高速网络是通信领域最近一次革新。IP网络容量以惊人的速度增长，全球范围的IP数据流量已经超过电话网络的流量，对于许多应用，IP流量的费用已经低于传统TDM服务的价格了。因此，人们越来越希望在IP网络上传输语音数据。于是，在VoIP技术上人们进行了大量的工作。然而，所有VoIP技术，本质上都具有革命性的变化，由此许多现存的电话基础设施将被基于IP的新机制取代。同时，今天的电话技术，不论是VoIP准备取代的部分，还是VoIP必须与之连接的部分，都十分复杂。对其上百种功能、上千种变化，人们不可能在短时间内完成这种革命性的工作。正是这样的背景下，我们决定采用了另一种思路实现语音数据的IP网络传输，即在IP网络上透明地不做任何数据解释地传输TDM语音帧。 本文为数字程控交换机研制了一种网络接口系统。该网络接口系统一端通过PCM基群串行总线连接数字程控交换机，另一端经RJ45口与以太网相连。网络接口系统用IP报头封装E1语音数据帧后，通过IP网络传送。由于该网络接口系统不做任何数据解释的透明的传输TDM语音帧，从而可以与原有的程控交换机实现无缝接入。与VoIP技术相比，本文的实现思路是一种渐进的非革命性，可以最大限度的保护在TDM设备上的原有投资，因此，它是对VoIP技术的一种有益的补充。更多还原

【Abstract】 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.更多还原