SDN development of optical networks exist different technical route

Comparative data networks SDN different optical network SDN has its own unique characteristics. First, due to the characteristics of the physical layer, the optical network control architecture itself has control forwarding separation. Secondly, centralized control, optical network has a mature network management, the path calculation unit (PCE) and other centralized management and control systems. Third, the light has the characteristics of a connection-oriented network, all traffic using pre-configured, without the controller forward packets according to the following service packets instant hair flow, reducing the controller performance requirements, with better network scalability . We can say that the optical network already has some characteristics of SDN for evolution to SDN has laid a good foundation. But on the other hand, optical network physical layer device programmability weak, resource virtualization and sliced ​​more difficult to achieve, so that the light is introduced SDN network technology there are some difficulties.

SDN optical network based on the characteristics of the development of optical network SDN take the evolution of ideas and data networks SDN differ. Meanwhile, the optical network backbone, metro and access layer development needs and the technology used different, SDN also introduced different technical route.

(1) Route One: enhancement based on optical network control plane, stressed north to open interfaces.

Backbone OTN, DWDM optical network equipment and other support capabilities better control plane, based on the existing ASON / GMPLS control plane and centralized path computation unit PCE technology, to interface to achieve SDN centralized control by extending and enhancing management and control capabilities and open PCE North devices, applications and services and provide open programmable upper network and applications. This route can better protect existing technology investment, and facilitate smooth network evolution. Since the optical network physical layer private information more difficult to south standardized interface protocol is relatively large, south to the interface may allow multiple interface technologies.

(2) Route II: Introducing openflow agreement, stressing the south to open interfaces.

For packet transmission PTN and PON access network equipment, it does not have the intelligent control plane, can be introduced directly on the device openflow agreement to achieve south to an open and standardized interfaces. This route due to the realization of the South to interface standardization, equipment and services in favor of decoupling, simplify network node function, reduce equipment costs, ease of operators for metro and access massive multi-vendor sites centralized management control. For existing network equipment has been deployed, will consider implementing a centralized controller capacities through network upgrade approach.