This page compares OTN Interfaces OTU1 vs OTU2 vs OTU3 vs OTU4 and mentions difference between OTU1, OTU2, OTU3 and OTU4 OTN interfaces. Here OTU stands for Optical Channel Transport Unit and OTN stands for Optical Transport Network.

ITU-T defines an optical transport network as a set of optical network elements (ONE) connected by optical fiber links, able to provide functionality of transport, multiplexing, switching, management, supervision and survivability of optical channels carrying client signals. [1] .

OTN test options let users generate and analyze OTN signals at full line rates of OTU4, OTU3, OTU2, OTU2e, OTU1e, and OTU1. The tests check for signal integrity, bit errors, FEC errors, and section and path overhead (SM/PM) errors/alarms.

Described in the ITU-T Recommendation G.709 (2003), OTN adds operations, administration, maintenance, and provisioning (OAM&P) functionality to optical carriers, specifically in a multi-wavelength system such as dense wavelength division multiplexing (DWDM).

ITU-T recommendation G.709, Interface for the optical transport network (OTN), is among the latest of these standards, and its aim is to address the transmission requirements of today’s wide range of services; namely, it was developed to assist in network evolution to higher bandwidth and improve network performance.

Fortunately the ITU Study Group 15 approved extending the G.709 optical transport network (OTN) standard to the next higher rate beyond the current OTU3 (43 Gbit/s) and defined OTU4 (112 Gbit/s) as the new optimal rate for carrying 100 GbE client services using generic mapping procedure (GMP).

ITU-T Recommendation G.709 Interfaces for the Optical Transport Network (OTN) describes a means of communicating data over an optical network. [1] . It is a standardized method for transparent transport of services over optical wavelengths in DWDM systems. It is also known as Optical Transport Hierarchy (OTH) standard.

2023年4月17日 · Visible OTU1/OTU2/OTU3 at the beginning of the design is to load SDH and consider. The base rate of the OTU2e, 10.3125G, is considered for carrying a 10GE signal.

The original OTU3 signal allows the mapping of four 10 GE LAN clients, if GFP-Based, G.709 rate-compliant (10.7 G) mapping is used. For multiplexing of overclocked signals, new mechanisms are defined: OTU3e1 and OTU3e2.

OTN is a Core Technology defined to provide end-to-end “pipes” to efficiently transport common access/transport client technologies, data rates and manage DWDM layers. The OTUk (k = 0 to 4) nomenclature is used to identify physical interfaces (ports).