What is MSTP

1 MSTP Concept

MSTP (multi-service delivery platform based on SDH) refers to the simultaneous access, processing and transmission of TDM, ATM and Ethernet services based on SDH platform, which provides a multiple service node for unified network management. In addition to the functions of a standard SDH transfer node, the multiple service transfer nodes based on SDH have the following main functional features.

(1) The Access function of TDM service, ATM service or Ethernet service;

(2) The transmission function with TDM service, ATM service or Ethernet service includes point-to-point transparent transmission function;

(3) The bandwidth statistic multiplexing function with ATM service or Ethernet service;

(4) The finger-matching function mapped to the virtual container of SDH with ATM service or Ethernet service.

The multiple service transfer nodes based on SDH can be applied to the access layer and the aggregation layer of the transport network according to the network requirements, and the application in the backbone layer is still to be studied.

Metropolitan Area Network is the focus of telecom operators, at present, there are a wide range of metropolitan area Network technology, which includes metropolitan area network based on SDH structure, metropolitan area network based on Ethernet structure, metropolitan area network based on ATM structure and metropolitan area network based on DWDM structure. In fact, SDH, ATM, Ethernet, WDM and other technologies are constantly absorbing the strengths of other technologies, each other, that is, to achieve rapid transmission, but also to meet the load of multiple services, in addition to provide telecommunications-level QoS, a variety of metropolitan area Network technology shows a trend of integration. (Computer science)

2 MSTP Working principle

MSTP can be the traditional SDH multiplexer, digital crossover Linker (DXC), WDM terminals, network two-layer switches and IP edge routers, such as a number of independent devices set into a network device, that is, based on SDH technology, a multiple service delivery platform (MSTP), for unified control and management. The MSTP, based on SDH, is the most suitable for the fusion node of the network edge to support the hybrid service, especially the TDM service. It is not only suitable for the lack of network infrastructure of the new operators, apply to the bureau or pop between, but also suitable for large enterprises and user stations. And even for the operators with a large number of SDH networks, multi-service platform based on SDH can support the packet data service more effectively, and help to realize the transition from circuit-switched network to packet network. Therefore, it will become one of the mainstream technologies of metropolitan area Network in the near future.

This requires that SDH be transformed from the transmission network to the integration of transport network and service network, that is, the integration of multiple service nodes. The foundation of MSTP is to make full use of SDH technology to provide protection and recovery capability and small delay performance, and to transform the support layer of Network service to meet the multiple service applications and realize the data intelligence support of two layer and three layers. The transfer node is merged with various business nodes to form the SDH service node, which is the integration of the business layer and the transport layer, which is called the Converged network node or the Multiple service node, and is mainly positioned on the network edge.

3 Characteristics of MSTP

(1) The bandwidth of the business flexible configuration, MSTP on the provision of 10/100/1000MBIT/S series of interfaces, through the bundled VC can meet the needs of a variety of users;

(2) According to the needs of the business, working in the Port group mode and VLAN mode, where VLAN can be divided into Access mode and trunk mode:

· Port Group mode: All systems and user ports on a single board are in one port group. This approach can only be applied to the business that is off the point-to-point. In other words, that is, any user port and any one of the system ports (because there is only one direction, so there is no need to start all the system ports, one is enough) is enabled, the network cable inserted in any one enabled user port, that with the account to enjoy all the bandwidth, the business can be opened.

· VLAN mode: Divided into Access mode and trunk mode.

The access mode, if the VLAN ID is not set, the port is in the working mode of the port group, all the system and user ports on the single board are in one port group.

If you set a VLAN ID, you need to set the Port VLAN tag. This is because the switching chip will increase the VLAN ID for the packets received, and then go through the system port to send the fiber to the port with the same VLAN ID on the end. For example, a user port VLAN ID is 2, the corresponding site's user ports VLAN ID should also be set to 2. This pattern can be applied to MSTP services in multiple directions, when each port in each direction is set to a different VLAN ID. The user port and system port in that direction are then placed in a virtual Network bridge (the VLAN ID of the virtual bridge must be the same as the Port VLAN tag).

(3) can work in full duplex, Half-duplex and adaptive mode, with the MAC address self-learning function;

(4) QoS settings:

QoS actually restricts the delivery of ports, and the principle is that the sending port has many send queues based on the business priority, and the delivery of various priority services is done according to the QoS configuration and certain algorithms. Therefore, when a port may send a business from multiple sources, and the total traffic may exceed the sending bandwidth of the sending port, you can set the QoS capability of the port and set the priority configuration of the various services accordingly. When QoS is not configured, bandwidth is distributed evenly and multiple sources of business try to transmit.

QoS is configured to specify the priority of each port when sharing the same bandwidth and the amount of bandwidth it occupies.

(5) Run the Spanning tree protocol independently for each client.

4 Advantages of MSTP

(1) At this stage, the demand of a large number of users or fixed-bandwidth line, mainly 2mbit/s, 10/100mbit/s, 34mbit/s, 155M bit/s. For these dedicated line services, can be divided into fixed bandwidth services and variable bandwidth services. For fixed bandwidth services, MSTP equipment from SDH integration of excellent load, scheduling capabilities, for variable bandwidth services, can directly on the MSTP device to provide end-to-end transparent transmission channel, fully ensure the quality of service, can fully utilize the MSTP two-tier exchange and statistical multiplexing functions to share bandwidth, save costs, At the same time, the VLAN partition function is used to isolate the data, and the service quality of the key users is ensured by different service quality grade (CoS).

(2) The convergence layer in the metropolitan area realizes the business convergence of the enterprise network Edge node to the center node, which has many characteristics, such as more nodes, more port types, more user connections and more port numbers. The MSTP network can realize the convergence or direct access of the IP routing equipment 10m/100m/1000m POS and 2M/FR Services, and support the business convergence scheduling, comprehensive loading, and has good survivability. According to different network capacity requirements, can choose different rate level of MSTP equipment.

5 Application of MSTP

MSTP technology has attracted much attention in the existing metropolitan area transmission network, has been applied in scale, and will be released as an industry standard in the industry. Its technical advantages are compared with other technologies: it solves the problem that SDH technology is not high in data service carrying efficiency, solves the problem that ATM/IP has low carrying efficiency and high cost for TDM service, solves the problem that IP QoS is not high, solves the limitation problem of RPR Technology network, realizes double protection, Improve the business safety factor, enhance the network concept of data service, improve the network monitoring and maintenance ability, reduce the risk of business selection, achieve lower investment, unified network, on-demand network advantages, adapt to the whole business competition demand, fast delivery of business.

MSTP enables the transmission network to be developed into a bandwidth operation network with independent operation value, using its own mature technical advantages to provide high quality and low bandwidth resources to meet the needs of metropolitan area bandwidth. Because of the characteristics of its multiple services, the metropolitan transmission network constructed by using B-ADM equipment can provide a wide range of bandwidth service content according to the requirements of users, MSTP the B-ADM equipment in the network dispatching, equipment and other aspects into operation concept, intelligent characteristics, realize the convenient and fast establishment of business, So as to further ensure the implementation of bandwidth operation to meet the market demand for metropolitan transport networks.

6 Summary

To sum up, because MSTP widely used in the metropolitan area Transmission network, has stimulated the city domain transmission network vitality, brings to the operator the greater benefit space. The major equipment suppliers are also constantly targeted at MSTP research and development, MSTP's connotation is gradually enriched. believe that the development of MSTP still exist huge space, the energy of its own technology also has great potential to wait for excavation. MSTP will play a decisive role in the construction of the city and become the first choice of network construction.