defines Optical Transport Network (OTN)
as a composed of a set of Optical Network Elements (3R
) connected by optical fibre links, able to provide functionality of transport, multiplexing, switching, management, supervision and survivability of optical channels carrying client signals.
ITU Standard G.709 is commonly called Optical Transport Network (OTN) or digital wrapper technology. OTN is currently offered in three rates, OTU1,OTU2 and OTU3.
- OTU1 has a line rate of approximately 2.7 Gbit/s and was designed to transport a SONET OC-48 or synchronous digital hierarchy (SDH) STM-16 signal.
- OTU2 has a line rate of approximately 10.7 Gbit/s and was designed to transport an OC-192, STM-64 or 10Gbit/s WAN. OTU2 can be overclocked (non standard) to carry signals faster than STM64/OC192 (9.953Gbit/s) like 10 gigabit Ethernet LAN PHY coming from IP/Ethernet switches and routers at full line rate (10.3 Gbit/s). This is specified in G.Sup43 and called OTU2e.
- OTU3 has line rate of approximately 43Gbit/s and was designed to transport an OC-768 or STM256 signal.
- ITU-T G.872: Architecture of Optical Transport Networks and Recommendation
- ITU-T G.873: Optical Transport Networks Requirements
- ITU-T SG15: Transport Networks Systems
- ITU-T G.664: General automatic power shutdown procedures for optical transport systemsITU-T
- ITU-T G.692: Optical interfaces for multichannel systems with optical amplifiers
- ITU-T G.709: Network Node Interface for the optical transport network
- ITU-T G.798: Characteristics of optical transport network equipment functional blocks
- ITU-T G.871: Framework for optical transport network recommendations
- ITU-T G.874: management aspect of optical transport network recommendations
- ITU-T G.875: OTN Management Information Model for the Network Element View
- ITU-T G.959.1: Optical Transport network Physical layer interfaces
1. Value of OTN for Network Convergence White paper: White Paper