Software-defined optical transport network make the network should be the need to change

Last year, China established the broadband strategy released two milestones: the 2015 basic realization of urban fiber-to-floor home in rural broadband into the village into the village, urban and rural households broadband access basic to 20Mbps and 4Mbps, some developed cities met 100Mbps; to 2020, a comprehensive broadband network covering urban and rural, urban and rural households to broadband access, respectively, 50Mbps and 12Mbps, the developed part of the city home users up to 1Gbps. This means that in the next few years, operators must continue to upgrade optical networks to achieve these goals. It is worth noting that the network bandwidth is growing at the same time, an endless stream of new broadband services, intelligent optical network flexibility and put forward higher requirements. Promotion of software-defined optical transport network (SD-OTN) to achieve network virtualization to maximize the use of network resources, so that an effective means of networks should the need to change.

Expansion and intelligent optical networks are two main trends of development. Cisco predicts that global data traffic in the next few years will show explosive growth. The next five years, the compound annual growth rate of global traffic will reach 66 percent, the growth rate in Asia as much as 76%. Nokia Communications released a research report pointed out that by 2020, the daily per capita consumption of personalized traffic will reach 1GB. Huawei predicts that the next three years, China backbone network traffic growth rate of up to 70% of the total bandwidth of backbone transmission network will reach 150Tbps, there may even exceed 200Tbps. In anticipation of traffic turmoil, carriers and communications companies are actively studying and deploying 100G and ultra-100G technologies. Single-carrier technology has been difficult to meet the needs of rapid development of traffic, the use of multi-carrier technology to improve spectral efficiency has become the focus of attention of the industry.

At the same time, with the growing number of broadband users, the type of intelligent terminal has become even more rich, cloud computing, big data, networking and other applications rise and gradually becoming more mature. Optical network support broadband services rendered dynamic trends. Traffic Storm is not evenly distributed, network traffic is often at different times are not the same, monthly, daily and even hourly flow situation is different. Such as big game day might have compared with the usual more users watch online live video; and if in the neighborhood during the day tend to be less traffic, more traffic at night, but during the day in the office area in general is more traffic, less traffic at night. If we can achieve dynamic network resource management and scheduling will undoubtedly maximize the use of network resources, thereby reducing overall costs. The conventional automatic switched optical network, generalized multi-protocol label switching architecture has been unable to meet this demand, an urgent need to introduce new technologies like software-defined optical transport network.

Software-defined optical transport network is the direction of the development of next generation optical transport networks, its design ideas from computing software-defined network (SDN). SDN is a new network architecture, network control plane and data forwarding plane will be separated, and programmable control. SDN architecture typical of three layers, the top layer of the application, including a variety of services and applications; middle control layer is mainly responsible for handling data plane resource scheduling, maintenance of network topology and status information; the underlying infrastructure layer is responsible for data processing based on the flow table, forwarding and status collector. Its main advantages as follows: standardization of hardware, reducing system hardware requirements, in order to achieve cost reductions; intelligent network management fully realized by the software to improve the ease of operation; simplifies network configuration process can rapid opening of new business.

SDN application in the main operators in the field of IP data networks, data centers and optical transmission network of the three scenarios. Among them, the software-defined OTN flexible pipes, dynamic bandwidth and programmable three characteristics, it is possible to achieve flexible scheduling hardware, network software dynamically adjust resources will help operators to manage network resources fine. Software-defined optical transport network of programmable optical network transmission controllers and programmable resource virtualization technology to provide efficient, flexible, open network services for different applications. It requires flexible optical, electrical function modules, programmable light system that supports OpenFlow standard control interface, providing an open API.

Currently, SDN standardization work is still in its infancy, software-defined optical transport networks need to overcome software programming optical path flexible switching, software-driven optical transmission adjustment key technology software extensions of optical automatic networking, as it continues to mature and widely applications, broadband network is expected to usher in a new round of changes.