MSTP adapts to the characteristics of the metropolitan area network. The metropolitan area network should have the following characteristics:
Support for multiple services
The metropolitan area network is located between the backbone network and the access network in the communication network model. The diversity of access services determines that the metropolitan area network should have the ability to support multiple services. Although the proportion of TDM service and ATM service in the total amount of public network services is getting lower and lower, it is still one of the important sources of stable income in telecommunication networks, dealing with traditional TDM and modern metropolitan area networks. The ATM service provides support; in recent years, the IP business has experienced explosive growth, and by 2002 it has accounted for nearly 90% of the traffic in the public network, and there is no indication that this growth momentum will slow down, instead with the NGN concept It is proposed that the IP business will grow at a faster rate. Therefore, modern metropolitan area networks should support multiple services such as TDM, ATM, FR, and IP.
Networking capabilities and networking flexibility
The basic technology of modern metropolitan area network should provide strong networking capabilities. In addition to supporting ring and line topology, it should also support networking, tree, star, multi-ring cutting and other networking methods, which can improve The scalability of the network makes it easy to configure the system environment flexibly and efficiently.
Reliability and stability
The basic technology of modern metropolitan area networks should provide reliable network fault detection, alarm and recovery capabilities to ensure that the network provides 24X7 services. The carrier-class fault recovery time should be less than 50ms.
Original equipment compatibility and interoperability
The basic technology of modern metropolitan area network should fully consider the compatibility of existing technologies and services, so as to fully guarantee the original investment of telecom operators. At the same time, considering the scalability of the network and the consistency of the protocol, the interconnection of devices from different vendors is also necessary.
Network maintainability and monitorability
Compared with the backbone networks at all levels, the most obvious features of the metropolitan area network are the uncertainty of service type, service flow, and traffic flow. Therefore, it is necessary to provide good network management capabilities. In the traditional telecommunication network management system, the transmission system and the service platform usually have their own network management systems, and even different services need to adopt different network management systems. The logical separation of the network management system seriously affects the maintainability and monitoring of the network. Provisioning and fault location and recovery become very difficult. This situation requires that the modern metropolitan area network infrastructure technology can provide a unified network management platform to facilitate network maintenance and management.
In order to reduce the complexity of implementation and management brought about by the excessive network protocol level, as well as the disadvantages of low work efficiency and poor system scalability, simplifying the network hierarchy, optimizing the network structure, and reducing the operating cost have become the basic technologies for the construction of modern metropolitan area networks. Urgent needs. For example, in the past, due to technical limitations, the transmission of IP services required mapping and conversion of multiple protocols such as IP/ATM/SDH/WDM. Now IP over SDH and IP over WDM have become an important trend in network development.
Although there is still a lot of controversy, the idea that "pure IP telecom network based on all-optical intelligent network is the ideal solution for future metropolitan area network" is gradually being accepted and recognized by more and more people. From the traditionally widely used "SDH+ATM" metropolitan area network to the all-optical IP intelligent network, operators must take into account both the advancement of technology and the compatibility of existing investments, compared with other metropolitan area network construction technologies. MSTP can adapt to the transmission requirements of voice, data, image and IP services, and has good cost performance. At the same time, due to the compatibility of MSTP and WDM, it is beneficial to smooth upgrade to all-optical network, which makes SDH-based multi-service. The Transmission Platform (MSTP) has broad application prospects and a large potential market for a long period of time.
Flattening of network protocols
