All-optical switching is the future direction of development, but also from the current development trend, this "future" is not far away. Many in the industry view: ROADM-based networking and scheduling is not sensitive to the rate applicable to ultra-high-speed optical networking and scheduling transmission systems, but also can greatly reduce power consumption and floor room. After years of gradual improvement technology, functionality and performance, CDC-F ROADM (ie colorless and directionless without conflict and supports flexible grid capacity reconfigurable optical forked Multiplexer) device has matured, basically solved the light layer networking encountered many problems. Some foreign operators in the deployment of 100G networks have begun to do large particles using ROADM traffic scheduling, a direct transition to an all-optical network. March 2015, Verizon announced the adoption of Ciena and Cisco's packet optical transport platform Metro 100G deployment, CDC-F ROADM technology for the first time to get a commercial scale. In the same month, Alcatel-Lucent announced that Verizon will use its latest CDC-F ROADM technology to upgrade Verizon's long-haul optical transport network.

Fiber optic transceivers may be in a response network traffic surge center of attention, but the link platform, panel-board equipment and other functions is the supplier of fiber optic transceivers can achieve product differentiation play space.

OTN's intelligent optical network will provide the ideal solution for the transmission of large-granule broadband services. Inter provincial transport network main trunk transport network, provincial trunk transport network, metro (local) transport network structure, while the Metro (local) transport network can be further divided into the core layer, convergence layer and access layer. SDH relative terms, the biggest advantage of OTN technology is to provide scheduling and delivery of large particles of bandwidth, therefore, at different levels whether to adopt OTN network technology, depending on the size of the primary particles dispatch service bandwidth. According to the network situation, primarily particles inter-provincial trunk transmission network, the province trunk transport network and metropolitan area (local) transport network core layer of scheduling is generally Gb / s and above, therefore, these levels can be given priority and scalability advantages OTN technology to build better. For Metro (local) transport network convergence and access layer, when major scheduling particles reach Gb / s order of priority can also be constructed using OTN technology.

OTN with WDM technology, large transmission capacity on the basis of the introduction of the SDH powerful operation, maintenance, management and assignment (OAM) capabilities, while addressing SDH function at the transport layer for lack of inadequate management and maintenance overhead. Using the embedded standard FEC, extensive maintenance and management overhead for large particles service access FEC error correction coding, improve the BER performance, increased light transmission span.

It should be said OTN and PTN are two completely different technologies, technically speaking we should say no contact.

The main advantage of OTN is fully backward compatible, it can build on existing SONET / SDH management functions on the basis of not only the existence of a fully transparent communication protocol, but also for WDM-end connectivity and networking capabilities, It provides a light layer interconnect specification ROADM, and added sub-wavelength aggregation and grooming.

OTN is based on WDM technology, optical transport network layer in an organization's network, it is the next generation of backbone transmission network. OTN is the next generation through a series of ITU-T recommendation G.872, G.709, G.798, etc. norms "digital transmission system" and "optical transmission system" that will solve the traditional WDM networks without wavelength / sub-wavelength services poor scheduling, network capacity is weak, weak protection and other issues.