400G is now supported on systems from many companies, providing an attractive alternative to using multiple 100G interfaces where higher throughput is required. 400G interfaces and optical modules have been challenging to develop, but these are rapidly becoming available from multiple suppliers. During 2018, companies will introduce second-generation 400G interfaces and optical modules, significantly increasing port density and ensuring strong market adoption by service providers and data center operators.

This is one of the many key findings in the latest Heavy Reading report, 100/400G Components Survey: 2018 Market Outlook, which is based on an exclusive worldwide survey that drew responses from over 80 professionals that represent 50 different telecom and networking equipment suppliers. The report charts the use of 100G, 400G, 800G and other interface speeds. It includes information about which interfaces are being supported, the importance of different 400G Ethernet port types, the use of PHY devices and 100-400G optical modules and the most important features when system developers select these modules. It also includes vendor rankings for PHY devices and optical modules, and valuable trend data using results from previous surveys.

The shift to cloud services and network virtualization is driving significant growth in network traffic and the speed of network interfaces is growing to match. 25G is replacing 10G, 100G is replacing 40G and 400G is replacing 100G for the highest bandwidth systems. 400G coherent interfaces are shipping for transport applications, including data center interconnect (DCI), metro and long-haul connections and 400G CFP8 modules are shipping for enterprise and some data center applications. This has enabled the market for 400G with 32% of those covered in the survey saying that their company is shipping systems with 400G interfaces. The next stage for the market and industry is reducing the cost of 400G with the introduction of QSFP-DD and OSFP modules during 2018 and 2019. So far QSFP-DD seems to be gaining more support.

100G is now widely supported on systems across the network, including data center, enterprise, metro and long-haul applications. QSFP28 is the leading 100G optical module form factor and is being used for most connections up to 40km reach. The growth in QSFP28 volume is driving down cost, particularly for data center connections up to 2km. The next steps for 100G are increased port density and further reduced cost. For this next step both MicroQSFP and SFP-DD are seeing significant support; however, it is unclear if either will replace QSFP28 in the next few years.

Physical layer (PHY) devices are required for any high-speed network interface. These can be located on the line card or the optical module and be implemented as merchant silicon, FPGA or ASIC. The use of DSP technology for coherent interfaces, as well as DSP or advanced analog processing for PAM4 interfaces, has significantly increased the value and importance of PHY designs. Broadcom continues to be the leading PHY supplier but is seeing growing competition from FPGA vendors, Intel and Xilinx, and a host of companies introducing PHY solutions that support PAM4 and coherent 16/64QAM interfaces.

The design and manufacture of optical modules has moved on significantly over the last few years with innovative assembly techniques and silicon photonics. The growth in volume for 100G and the new emphasis on 400G has given optical module suppliers a significant boost over the last year. We are now seeing the results with several vendors challenging Finisar as the leading optical module supplier, including Intel for short reach applications and Acacia for transport applications.

Network operators and system manufacturers already have a wide choice of suppliers for 100G optical modules and access to 400G solutions for both enterprise and transport applications. The industry is planning to support a wide of interfaces and speeds including 25G, 50G, 100G, 200G and 400G, and many are already looking toward 800G interfaces and the benefits they can bring. There is also a growing number of suppliers shipping 100G solutions, investing in 400G and planning solutions for 800G. The results of the survey show that the market is looking forward to using the new interfaces and optical modules that will enable higher port density and promise lower costs and power consumption particularly for 100G and 400G.

— Simon Stanley, Analyst at Large, Heavy Reading