【摘要】 指出了目前SCP在实现方面存在的缺陷，针对其结构和运行机制，提出其软件具有系统级与呼叫级的两级并发性，并基于这个两级并发模型对它的软件容错途径进行了深入的探讨与研究。首次提出了应用软件出错情况下保证所有在线呼叫可靠处理的容错目标，并在SCP系统级与呼叫级两个并发层次上给出了切实有效的容错策略或算法。最后对SCP软件系统有效度的估算进行了进一步讨论。更多还原

【Abstract】 SCP is the critical part in the iN system, and its dependability will affect directly the qualityof service (QoS) of the whole network. In this paper, the shortcomings of the existing implementations are analyzed, and the Two-Level Concurrency Model of the SCP software are presentedaccording to its architecture and running mechanism. Based on this model, the issues about software fault tolerance of the SCP are deeply discussed, and the corresponding strategies and algorithms for the fault tolerance are given. At last, a further discussion on the system effectivenessof the SCP software is given, which is based on the Markov model.更多还原