It's an exciting time for this industry! Demand for 10GbE SFP+ transceivers surged between 2010 and 2014 after starting shipments to Google in 2007. In the past five years, more than 40 million SFP+ 10GbE optical modules have been sold, more than half of which are used in large data centers. 40GbE has been shipped in batches since 2013. Data analysis predicts that its shipments will exceed 2.5 million this year, of which more than 75% are sold to Web2.0 customers.

　　From 2016-2021, the demand for 40GbE and 10GbE optical modules will remain strong, but it is the upcoming demand for 100GbE in data center applications that is really exciting.

　　It is based on the causal relationship between the total bandwidth of the optical link and the Internet traffic to make predictions. This method is very effective in predicting the demand for DWDM optical devices in 2006-2014, but it is difficult to use this method to predict the demand for Ethernet transceivers in 2010-2014. Additionally, another challenge is that historical traffic growth data within large data centers is not readily available. Fortunately, Google recently released this kind of data:

　　Google's data shows that traffic has grown 50-fold over the past seven years, equivalent to an average annual growth rate of 75% -- significantly higher than the growth in global Internet traffic. However, the figures also show that traffic growth in 2014 was around 50% -- down from 80% growth in 2012.

　　This is individual company data, but it is very important. This shows that the changes in the internal traffic of the giant data center are similar to those of other networks: the network of telecom operators, the network of scientific research institutions, and the direct connection between the backbone network and the backbone network.

　　The report shows that the size of the data tsunami is not an incremental process, and eventually it will cap. This is in accordance with the law. Many systems, such as networks, markets, or economies, follow the famously elongated S-curve, with growth rates slowing as they mature. Giant stars exploding into supernovae are rare exceptions.

　　The analyst firm noted that its latest forecast for Ethernet optical transceivers in data centers is based on the assumption that traffic growth will decline from 50 percent in 2015 to 30 percent in 2020. Note again: traffic will continue to grow rapidly, but its relative growth rate will slow down.

　　Global Ethernet optical transceiver sales are also expected to grow from $1.6 billion in 2014 to $4.9 billion in 2021, with more than 50 percent of sales coming from large data center applications. By 2019, the annual shipment of Ethernet optical transceivers will exceed 50 million, of which large data centers will consume about 30%.

　　Interconnections between data centers drive DWDM optics demand. In 2014, 100G and 400G DWDM ports for large data center interconnects accounted for 10% of total DWDM ports; by 2021 this proportion will rise to 20%.