The Study Of Circuit Emulation Service In Packet Transport Network

In order to adapt the needs of IP-based services, the process of IP-based local network continues to accelerate, the IP/MPLS network has begun to take shape in China. The traditional TDM services will gradually be carried on the Packet Transport Network (PTN) instead of traditional multi-service equipment (MSTP). Carrying TDM services over PTN is often called Circuit Emulation Service (CES), due to the CES service across the circuit domain and packet domain, the clock information of the CES service has gone during the transmission, and therefore it need to be recovered at the end of the node clock information. Moreover related alarms and performance monitoring capabilities in PTN is not efficient, the operational level of alarm information can’t be reflected in the network management system. Therefore, the study of packet network circuit emulation services has important significance.Based on the summarizing of the implementations and technical standards on CES, this paper research the major technical difficulties of the CES in the PTN, such as the clock recovery problem and the monitoring and maintenance of the CES. This paper carried out some related research through the targeted tests. First, this paper study the bandwidth and latency of CES and carry out some advice about the planning of the bandwidth and latency. Secondly the paper also study the characteristics of the CES in PTN. In order to study the impact on the clock, the paper simulated some problems that may occur in the network. Finally, the paper proposes a monitoring model to improve the quality of the CES in PTN.