#Internet backbone diagram plus

The Optical Channel Data Unit (ODU) contains the OPU overhead and payload area, plus additional overhead such as BIP8, GCC1/2, Tandem Connection Monitoring (TCM), and so on. The OPU overhead is associated with the mapping of client data into the payload area. The payload area of the OPU structure is comprised of end-user services such as IP, Ethernet, or any other protocol. The Optical Channel Payload Unit (OPU) contains the payload frames. It has two parts: a digital structure and an optical structure. The Optical Transport Module (OTM) is the information structure transported across the optical interface. The OTN wrapper is made up of several components in a hierarchy as depicted in Figure 1. Hundreds of thousands of OTN ports have been deployed and are carrying mission-critical traffic from the edge into the metro and core of the network, as well as in submarine applications. To date, OTN technology has been extensively deployed in networks across the globe, with increasing scope across a wide spectrum of applications. OTN-enabled technology often underpins next-generation optical networks with its ability to support flexible packet technologies that include new Ethernet interfaces, Multi-Protocol Label Switching (MPLS), Segment Routing, and Time Sensitive Networking (TSN) to name a few. In fact, OTN has been optimized to support Ethernet-today’s most popular client service-from 1GE to 400GE. Since its inception in 2001, OTN has continued to evolve beyond a simple SONET/SDH wrapper. The enhanced multiplexing capability of OTN allows different traffic types, including IP, Ethernet, storage, digital video, and SONET/SDH, to be carried over an OTN framing structure-a key reason for the adoption of OTN. OTN is commonly called a ‘digital wrapper’ as it wraps each client/service transparently into a container for transport across optical networks, preserving the client’s native structure, timing information, and management information.

Internet backbone diagram