SC328 - Standards for High-Speed Optical Networking

Sunday, 06 March
09:00 - 13:00

Short Course Level: Intermediate


Tom Huber, Nokia, USA

Short Course Description:

This course provides details of a complementary set of standards for high-speed optical networking including the Optical Transport Network (OTN) standards developed by ITU-T Study Group 15, higher speed Ethernet (100 Gb/s and beyond) standards developed by IEEE 802.3, and the Flex Ethernet implementation agreement developed by the Optical Internetworking Forum (OIF).

Initially developed for DWDM transport of SONET/SDH, OTN has evolved to provide a common convergence layer for IP and Ethernet traffic. The standard has moved from a combination of point-to-point DWDM line systems and metro ROADM networks to a full, end-to-end managed network. OTN standards have evolved to support line interface rates, originally at 2.5 Gb/s to 40 Gb/s optimized to carry SONET/SDH clients, to now extend from 10 Gb/s to multiple 100s of Gb/s using coherent modulation, increasingly carrying Ethernet (100 Gb/s, 200 Gb/s, 400 Gb/s) as the dominant client. DWDM networks based on OTN have provided a common convergence layer for SONET/SDH, IP, and Ethernet traffic. The ODUflex container allows the OTN to carry client signals at any rate, allowing support of data center interconnect and storage-area networking protocols such as Infiniband and Fibre Channel, video distribution signals including various SDI and DVB_ASI signals, and mobile fronthaul/backhaul. Recent OTN extensions have introduced a general-purpose approach to allow large aggregate signals to be composed of multiple wavelengths over the same fiber route, where the wavelengths may be different modulation formats and bit-rates according to the reach required for each connection, and to take advantage of flexible grid networks. This is being done both to improve spectral efficiency and to support higher rate clients such as 400 Gb/s Ethernet and Flex Ethernet, which can create large OTN client signals through the bonding of multiple Ethernet PHYs.

Several additional industry efforts blur the lines between OTN and Ethernet applications, including the OIF 400ZR interface, the OIF 800ZR project, the IEEE 802.3ct 100G PMD and IEEE P802.3cw 400G PMD under development for operation over DWDM systems, and ongoing IEEE 802.3 work on 800G and 1.6T interfaces, all of which are primarily targeted at data center interconnect.

In addition to carrying Ethernet as an OTN client, in the cases where OTN line interface rates and Ethernet rates are common, the same pluggable modules are used for both Ethernet interfaces and OTN client (grey optics) interfaces.

The Flex Ethernet implementation agreement provides a way to create a range of Ethernet client rates that may not correspond to Ethernet physical layer PHY rates. This enables a variety of network scenarios including non-LAG bonding of Ethernet PHYs to support larger flows, matching of Ethernet rates to transport network line rates that may vary with modulation format and reach, and channelization of multiple Ethernet flows within a group of bonded PHYs.

OTN is being deployed by many operators for their next generation network builds. This course will cover the basic features of ITU-T Recommendation G.709, with specific emphasis on the recently added interfaces and capabilities, such as “FlexO”, which provides a group of OTN interfaces that can distribute a large OTN container over multiple wavelengths in a DWDM system, or over multiple PHYs for high-bandwidth “grey optics” interfaces.

You will learn how Ethernet, Flex Ethernet and other traffic can be carried by an international standard-based digital wrapper solution. You will develop an appreciation for the flexibility provided in the latest OTN standards to transport a wide variety of client signals and to efficiently manage bandwidth.

Short Course Benefits:

This course should enable you to:

  • Understand the mapping mechanisms used by OTN to transport major client signals.
  • Understand the capabilities provided to manage client signals and optical media/wavelengths.
  • Understand the structure and format for higher rates of Ethernet.
  • Learn about a range of industry efforts to incorporate DWDM technology and coherent modulation for a variety of applications.
  • Understand the Flex Ethernet implementation agreement and the network configurations that can be supported.
  • Know where to look to find more information about ITU-T G.709, IEEE 802.3 standards, and the OIF Flex Ethernet implementation agreement.
Short Course Audience:

This course is intended for anyone who designs, operates, or supports metro and/or long haul optical networks for any application space (including telco, data center interconnect, storage area networking, and video distribution) and who need to understand the new interfaces and capabilities specified by standards on OTN, high-speed Ethernet, and Flex Ethernet. Students should have a basic understanding of transport networking technologies (e.g., SONET/SDH or OTN) and Ethernet.

Instructor Biography:

Tom Huber is part of the optical standardization team at Nokia. He received his B.S. (Electrical and Computer Engineering) from the University of Notre Dame and M.S. (Computer System Engineering) from the Illinois Institute of Technology. He has been active in optical networking standardization for more than 20 years. He is associate rapporteur of ITU T Q11/15, Signal structures, interfaces and interworking for transport networks, and has been nominated as a vice chairman of ITU-T SG15, Networks, Technologies and Infrastructures for Transport, Access and Home. He also is active in the Optical Internetworking Forum (OIF) and IEEE 802.3.