O & M and Management of ASON Networks

The ASON technology introduces the control layer in the traditional transmission network to realize the automatic discovery of nodes and connections and the automatic establishment of connections, multiple Fault Protection and recovery mechanisms are selected. This kind of intelligence has brought great changes to the O & M of traditional networks. Many tasks of Traditional transmission network management and O & M require manual participation, while most tasks of ASON networks are automatically completed, this kind of change is not just a simple manual to automatic, but a conceptual change. <BR>
O & M and management of traditional transmission networks

Network O & M and management mainly includes circuit scheduling, alarm analysis, fault management, performance analysis, resource management, data processing, and network optimization. In a hierarchical transmission network for O & M and management, most of these tasks are completed by the staff.

When network administrators perform circuit scheduling, they need to check which of the reachable routes are idle when they know the Source and Destination addresses of the required circuits and the required bandwidth, then, select a route from the idle Routes Based on Traffic balancing, minimum hop count, minimum cost, or other constraints for configuration. During the specific configuration process, you also need to select the appropriate time slot to configure cross-connection for the passing nodes along the route according to the required bandwidth. If the required circuit cannot be configured in a ring, the cross-ring configuration is required. In this way, the routing selection and cross-connection configuration are more complex and takes a longer time. For example, you need to configure a 2 m circuit from Beijing to Shanghai and find the route: Beijing-Wuhan-Shanghai, the circuit needs to be configured in the protection ring of the Two-fiber Bidirectional multiplexing segment (the speed is 10 Gb). To illustrate the configuration process, we use the Wuhan node as an example to describe how to configure the circuit, 2 MB of inbound and outbound time slots must be specified, and the position of the 2 MB of inbound/outbound time slots in the 155M must be known (63 2 MB of 155M ), you must also specify the position of the 155M in the 10g (10g Includes 64 155 M). In this way, you can configure a cross-connection when the first 155M gap of 2 Mb is specified in the inbound/outbound nodes. It can be seen that when the number of nodes passing through the circuit is large, the configuration is very complex and time-consuming, and it is not conducive to unified planning and network optimization.

Alarm Analysis and fault management in the traditional transmission network alarm analysis, mainly rely on the simple alarm handling provided by the manufacturer's network management system, and fault locating and management are not at all. This is not a big problem in the pure SDH system, but in the SDH + WDM system, because the underlying fault is not only reflected in its own system, it is also reflected in multiple associated systems on the upper layer. Without fault locating, multi-layer Protection Switching cannot be coordinated, and manual fault handling is also difficult. In short, the simple alarm analysis and lack of fault handling capabilities bring great problems to network management and O & M. In the case of faults, all affected services need to be solved in real time or quasi real time, this requires fast Fault Locating and handling. This is why most carriers are very concerned about fault locating.

Network Optimization and Resource Management: network optimization is generally performed in two situations. One is that resource allocation is unreasonable or insufficient; the second is to improve other network pointers (such as O & M assessment pointers and network security pointers ). The traditional transmission network is a ring network. Therefore, if you configure routes in a ring, you can select only two routes. Generally, the routes selected are routes with the least number of hops, this saves board resources. Due to the imbalance of business development, this routing result will lead to a high utilization rate of local resources in the ring network, while the utilization rate of other parts is too low, this phenomenon is more common in Ring Networks with a large number of nodes. Therefore, to optimize the resources used by the network, you need to adjust the circuit so that resources can be reasonably used. It can be imagined that this is complicated when the business has been configured and the scheduling needs to be completely manual, and the risk of manual reconfiguration of online businesses is also high, as a result, only local optimization is performed, but expansion or large ring removal are continuously performed. In addition, the Operation and Maintenance pointers are sometimes in conflict with the goal of resource optimization. Security pointers are the most important pointers in the network. To ensure the security of some important circuits, it can defend against dual-point faults, or avoid the situation where a dual-point fault occurs. The circuit between two points (a local circuit) it should be allocated to unrelated routes that are not on two or more routes in the same ring. Because two routes that are not on the same ring, there must be one that is not optimal, in addition, the cost may be high, which will inevitably lead to a waste of network resources. Therefore, such adjustments are often caused by faults that have affected important services, or a preventive measure that predicts a high probability of failure on a single ring, such as the impact of natural disasters such as a hurricane or a flood.

Performance analysis and data processing: This is an indispensable part of daily maintenance and management. It extracts useful data from a large number of tables for analysis and processing, and then analyzes the circuit utilization rate and channel organization diagram, fault probability table, resource utilization, and so on. Such analysis reports are generated on a weekly, monthly, and quarterly basis. In addition, for the convenience of analysis, data analysis compared with the same period in previous years is also often required. In traditional O & M, this part of the work needs to be done manually, resulting in heavy workload and error-prone.
　　
O & M and Management of ASON Networks

Compared with traditional transmission networks, most of the O & M and management tasks are manually completed. The O & M and management tasks of ASON networks are automatically completed.

Circuit scheduling in the ASON network is very easy. You only need to know the source and target addresses, bandwidth requirements, Protection Switching level, and specify the specific target (such as the minimum cost and the minimum number of hops) of the route selection ), the control plane automatically selects an optimal route that meets the conditions as required. In some special cases, you need to specify the nodes/links that must pass through, nodes/links that must not pass through, whether service balancing is required, and whether SRLG (shared risk link group) is required) unrelated and other constraints.

In the ASON network, alarms are handled and analyzed to automatically locate faults. The fault locating includes two levels: hardware faults and line faults. The fault-free addressing function enables the ASON network to support coexistence of line protection and service protection, and supports multi-granularity and multi-layer network protection. At present, the fault locating function of SDH-Based ASON has been initially implemented. The fault locating function of OTN-Based ASON is complicated because it involves the processing and analysis of pure light layer alarms.

ASON has abundant Performance Analysis and powerful data processing functions. It is convenient to provide statistics and analysis of resource utilization, channel organization chart statistics, and network failure analysis, that is, to analyze the network damage in the case of single point of failure in the network, point-by-point traversal to determine which point is of the highest importance. You can also traverse any two points to provide protection for specific segments in the case of single point of failure (spof. Likewise, you can analyze faults in multiple zones. In addition, you can compare the link resource utilization and display the service path. You can also analyze and process the resource usage of a link or node separately, and provide suggestions for upgrading and resizing.

Compared with traditional transmission networks, the network optimization planning tool is a relatively independent part of ASON. There are many functions of network optimization planning, which can be used for initial network planning, technical and economic feasibility analysis on the proposed network scheme, and sensitivity analysis on the influencing factors, this article draws the most influential factors for CAPEX and OPEX, and gives special considerations for them. It can be used for resource optimization and re-routing of resources that are not reasonably used, so as to make reasonable use of resources across the network. It can also be fragmented to save network resources. Optimization Planning is generally performed offline, but it has an interface with the current network, and can collect online data for analysis and processing, use these materials to optimize and analyze the current network, and download the optimized data to the network management one by one to dynamically manage the network optimization. There are many objectives for the optimization plan, including improving network survivability, improving resource utilization, reducing investment, and increasing investment-income ratio. Specific optimization can be performed based on a single goal or multiple targets, multi-objective Optimization is commonly used, that is, taking the most important goal as the optimization goal and other objectives as the constraints for Comprehensive Optimization and planning.

In addition, business management is a unique part of ASON, because it can introduce some new businesses, such as OVPN, BoD, multicast, and SLA services, this requires management and maintenance of these businesses. This requires not only security settings, but also adjustment of service levels and bandwidth to the customer at any time as needed. These adjustments are made online, it will not cause damage to the business.
　　
Benefits and problems of O & M changes

It is not difficult to compare. Traditional Network O & M and management require the participation of a large number of staff, from routing selection to cross-connection configuration, from fault locating to various data processing, the direct participation of network management and O & M personnel is indispensable in every step. This will undoubtedly waste a lot of manpower and may fail to achieve unification or perfection during route selection and optimization planning. However, on the other hand, we have also trained a large number of staff who are very familiar with the "status" of the network. In the case of a network failure, as long as there are surplus resources in the network, the network administrator can recover the fault. However, the intelligence of the ASON network greatly simplifies O & M and management, and almost all actual operations are completed by the Software. What O & M network administrators need to do is no longer actual operations, instead, you are familiar with and familiar with the use of network management software, especially how to set various attribute parameters in network management software, such as SRLG, protection attributes, and costs, also, you need to know what role these attribute parameters play in the actual algorithm. Because manual configuration and computing are not required, O & M network administrators can easily perform routine maintenance work. However, they only know some attribute parameters and basic operations, if you do not have a deep understanding of the operating principles of ASON, you may be overly dependent on intelligence, and a long time may cause unfamiliar networks, in this way, when a software fault or other unpredictable major fault causes intelligent protection to fail, it is possible that effective measures cannot be taken to manually recover the network in a timely manner.

From a dialectical point of view, it is precisely because the traditional transmission network is not intelligent that network O & M and management require the participation of staff. Therefore, a large number of "intelligent" O & M and network management personnel have been trained. However, the intelligence of ASON networks can easily make O & M and management personnel dependent on intelligence. Therefore, ASON automation puts forward new requirements for O & M and management personnel on the basis of reducing the workload, asking them not only to understand how to operate ASON's network management system, but also to skillfully set relevant parameters, it is more important to understand the principles of parameter settings, such as routing and protection and recovery, and to regularly collect statistics, process, and analyze various network data to clearly understand the network status; at the same time, it puts forward higher requirements for ASON equipment in terms of the reliability of software and hardware platforms, smart manageability, O & M and management functions, and ease of operation and manageability, in particular, it puts forward special requirements for O & M and management in the case of control plane faults, which not only requires the failure of control plane to not affect normal business, but also requires the control plane to have a certain degree of self-healing.

The use of the optimization planning function of ASON is a tool that must be carefully mastered by network administrators and O & M personnel. Most of the network running statuses and data processing and analysis require the optimization planning tool. At present, the ASON optimization planning tool is an important basis for distinguishing the product maturity of different equipment manufacturers, and also the key content that needs to be continuously improved and improved in O & M. The maturity of optimization planning tools directly affects the O & M management of ASON networks.
　　
Summary

ASON has brought revolutionary changes to network O & M. Compared with traditional transmission networks, its intelligence can save a lot of manpower. The reason for putting forward a dialectical view is that ason o & M and management do not deny that ASON has brought convenience in O & M and management, but affirm that ASON has brought revolutionary achievements in network management and O & M. As long as O & M and network management personnel can fully master their working principles, they will certainly benefit from this revolution. Article entry: csh responsible editor: csh