Technology

Optical Transport Network

The Optical Transport Network (OTN) defined in ITU G.709, also commonly called “digital wrapper” is a next-generation, industry-standard protocol providing an efficient and globally-accepted way to multiplex services onto optical light paths. It allows network operators to converge networks through seamless transport of the numerous types of legacy protocols, while providing the flexibility required to support future client protocols.

The enhanced multiplexing capability of OTN allows different traffic types—including Ethernet, storage, digital video, as well as SONET/SDH—to be carried over a single Optical Transport Unit (OTU) frame, either OTU-1 at 2.7 Gb/s, OTU-2 at 10.7 Gb/s, OTU-3 at 43 Gb/s, or OTU-4 at 112 Gb/s.

In addition to multiplexing services, OTN adapts to ever-changing customer requirements and provides more effective optical network management. Since the protocol allows for full performance-monitoring of all the multiservice traffic mentioned above, it is ideal for carrying 10 Gigabit Ethernet (GbE) and offers operators an excellent model to manage performance and troubleshoot Ethernet services.

Because OTN is a fully-transparent protocol, adapting existing services is simple. OTN leaves current OSS/BSS solutions intact, utilizes all available tools and automation, and requires little to no retraining. OTN’s cost-effectiveness, ease of implementation, and relative lack of complexity provides companies with a straightforward, painless solution to evolving network needs.

OTN Advantages

• Insulates the network against uncertain service mix by providing transparent native transport of signals encapsulating all client-management information
• Performs multiplexing for optimum capacity utilization, thereby improving network efficiency
• Enables network scalability as well as support for dedicated Ethernet services with service definitions for 1GbE, 10GbE, 40GbE, and 100GbE, with higher rates beginning specification
• Provides multi-layer performance monitoring and enhanced maintenance capability for signals traversing multi-operator networks
• Enables automated mesh connectivity and 50ms mesh restoration for Ethernet, OTN, SONET and SDH clients when combined with intelligent control plane