The backbone network in the post-Moore era is facing huge expansion pressure, which is the first hurdle faced by operators; once the capacity of the backbone network is expanded, once a failure occurs, the impact will be more extensive, and reliability becomes the second hurdle; in addition, The continuous expansion of the network brings increased complexity of operation and maintenance. How should operators go through these three obstacles?
The flow surge, the pressure of expansion is large
The development of broadband services such as video has continued to increase users' demand for Internet bandwidth, and the pressure on backbone network capacity has become increasingly significant. However, the operator's investment in expanding the backbone network is a huge sum. At the same time, the continuous decline in ARPU per megabit has become a trend, and some Internet applications even divert the profits of existing telecommunications services, which prevents operators from having sufficient investment motivation.
How to reduce the expansion pressure of the backbone network? Improving node capacity, optimizing network architecture, and multi-layer collaborative planning of the network may be feasible measures and options.
Improve node capabilities
The most traditional and direct network expansion method is to upgrade the port rate and increase the device capacity. At present, 40G has begun commercial use. With the continuous growth of business traffic, 100G has gradually become a hot spot in the industry. The upgrade of the port rate will inevitably require the increase of the device capacity. T-bit routers and OTN devices have emerged. However, the above-mentioned expansion methods will result in high pressure on core node capacity and high cost. Therefore, in addition to improving node capabilities, operators must also consider expanding the backbone network capacity from the perspective of network architecture optimization.
Optimize network architecture
The traditional hierarchical network is a relatively economic network construction model. When the network traffic is small, the router can achieve the convergence of the traffic through statistical multiplexing, and solve the scalability problem brought by the full interconnection. However, with the increase of network traffic, core routers face the pressure of frequent expansion, which restricts the development of the network. And in the backbone network, more than 50% of the traffic is transit traffic. This traffic is forwarded many times by routers, consuming a lot of expensive router ports, and the hierarchical network construction mode will no longer be economical.
When the traffic between the two routers is close to the link bandwidth, it does not make sense to converge through the intermediate router, so you can use the direct connection between the routers. When the intermediate aggregation router is replaced, the network hierarchy is reduced. When there is only one hop between the routers of the backbone network, the network is completely flattened.
For example, in a hierarchical network, service traffic is sent hop-by-hop on the router. Each packet is forwarded just like a vehicle at a crossroad is scheduled according to traffic lights. When traffic is small, it has better performance. The direct connection between routers through the optical layer is like an overpass. There is no traffic light, which can realize the rapid scheduling of large-grained services. Even if the traffic is large, it can ensure better performance.
The direct connection between routers simplifies the network architecture, reduces capacity expansion pressure, saves interconnection costs, enhances network scalability, reduces network delay and jitter, and improves service quality.
Taking China Telecom's ChinaNet backbone network as an example, the flattening process of gradually upgrading its large-volume access nodes (such as Hunan) to a class-like core point has shown obvious economic benefits. In 2010, the expansion from 9 core nodes to 15 nodes has been completed. In the future, more core-like nodes will be expanded, and gradually evolved into a flat backbone network.
Multi-layer collaborative planning
The growth of traffic requires the network to evolve flat. How can there be steps to evolve efficiently?
The flattening of ChinaNet's backbone network is based on human observation and experience. In order to improve accuracy and efficiency, the industry is currently focusing on implementing flat network deployment through multi-layer planning. Operators establish direct links between routers based on the results of multi-layer planning tools during network deployment or network optimization.
The traditional network planning is a layer-by-layer planning, and the router network and transmission network are planned separately. Due to the limited information exchange, the result of the whole network planning is not the most economical. In addition, some operators believe that the use of expensive router ports should be minimized in the network. On the one hand, it is due to the relatively high cost of the router; on the other hand, not all traffic needs to be processed by the core router. By establishing a direct link between the edge routers, the ports of the core router can be reduced, thereby saving equipment costs.
Multi-layer planning is to plan the router network and the transmission network at the same time, so that resources can be rationally allocated in the network. Small-grain services are scheduled through the core router, and statistical multiplexing is used to improve efficiency. Large-grain services are directly transmitted at the optical layer, thereby improving The efficiency of the entire network. Using multi-layer planning tools to achieve flat network deployment is more accurate and efficient than the experience-based approach, and supports the gradual evolution of the network. At the same time, multi-layer planning tools can effectively support the entire network TCO analysis, and simplify the complexity of capacity expansion through incremental planning.
Take the backbone network of an operator as an example. The backbone network consists of 106 nodes, including 20 core nodes and 86 tandem nodes. Assuming that the wavelength bandwidth between the nodes is 10G, the service matrix is ​​considered at an annual increase rate of 60%. With the increase of traffic, the cost difference between flat network construction and hierarchical network construction is increasing. By the eighth year, flat The cost of network construction is only 61.62% of the layered network construction. With multi-layer planning tools, planning tasks that originally took several months to complete can be completed in a few days.
Because the network planning has a certain period, and the data service is very sudden, there is a need for dynamic planning on the network. Dynamic planning needs to increase traffic detection, multi-layer PCE, Bypass server, etc. There is a lot of standardization work, which is still far away. The semi-automatic network flattening method combining traffic detection and network management operation is a more feasible option.
The fault has a wide range and affects customer loyalty
40G has already begun commercial use. The 40G link carries thousands of services. Link failure will affect many services, and customer loyalty will be greatly reduced. How to improve the reliability of the backbone network is another challenge facing operators.
With the continuous development of router fault recovery and protection technologies, in theory routers have been able to protect services when the network fails. However, in actual deployment, due to limited transmission resources, it is difficult to configure a fast protection recovery path, and when the transmission link fails, it will cause a large number of alarms and routing oscillations at the routing level, which will have a great impact on the router.
ASON can solve the multi-point failure of the transmission network through the fast rerouting of the optical layer, but lack of cooperation with the router, there may be situations where the protection is unsuccessful or multiple protections. If it cooperates with the router through the GMPLS UNI interface, it can realize the cooperative protection of the multi-layer network, on the one hand, it can speed up the protection of services, on the other hand, it can save too much protection resources. In addition, during multi-layer network planning, the reliability of the backbone network can be improved by sharing the constraints of the risk link group.
Difficult operation and maintenance
Suppose an operator has more than 6,000 alarms at the WDM level every day, and at the router level, the alarms will multiply and increase to more than 20,000. Such a large number of alarms causes the root cause alarm to be submerged, and it becomes very difficult to quickly find the root cause of the alarm. This is because an alarm in the transport layer usually generates more than 10 times the alarm in the IP layer, and the IP network and the transport network are managed and maintained by different departments. It is difficult to know the bearing relationship between the IP layer and the transport layer, and the IP Correlation of alarms between the layer and the transport layer. Through the coordinated operation and maintenance of IP and optical layer, as well as a unified database, it is easy to maintain the bearing relationship between IP and optical layer and the correlation of alarms, which can shield a large number of derivative alarms, quickly find the root alarm, and locate the fault From hours to minutes.
Through unified network management and GMPLS UNI, rapid deployment of services can be achieved, and the time for service opening can be shortened from months to days, so as to respond to customers faster and win the market.
In summary, in the case that traffic is growing with Super Moore's Law, it is not only necessary to improve the capacity of a single node, but also to optimize the network from the perspective of network architecture; in the trend of flat architecture, IP and optical multi-layer collaborative planning tools It can guide the deployment of a flat network, improve network efficiency, and reduce network costs; while multi-layer collaborative protection and operation and maintenance greatly improve network reliability and operation and maintenance efficiency, and reduce operation and maintenance costs. Therefore, the cooperation between IP and optical in terms of traffic, protection, and operation and maintenance is the best choice to deal with the challenges of the backbone network in the post-Moore era.
Hengstar's LED backlight enhanced high bright digital signages is designed for semi/full outdoor information display. It built-in with a video decoding board or a network video decoding board, can display files preset in flash drive and can also display programs online. Sizes from 32'' to 65'', 1000-3000 cd/m2 brightness are available. Display's constructure meet NEMA4 (IP65) and NEMA4X (IP66) ingress protection grade according to different environment conditions. Our sunlight readable displays have good considering of heat elimination, ensuring the monitor durable and good performance. The sunlight readable signages have been widely applied to railway station, bus
Signage Display,Outdoor Digital Signage,Floor Standing Digital Signage,Wall Mounted Digital Signage
Shenzhen Hengstar Technology Co., Ltd. , https://www.angeltondal.com