The Optical Transport Systems market increased by 15% year-over-year (Y/Y) in 3Q2025, driven by robust demand across all major customer groups and technology segments, according to Dell’Oro Group’s recently published 3Q25 Optical Transport report. The most significant growth was seen in Cloud Providers (58% Y/Y), while the DWDM Long Haul segment grew 24% Y/Y.
- Direct sales for data center interconnect (DCI) continued to be the driving application for optical equipment sales, growing 34% Y/Y.
- Non-DCI also performed well, rising 7% Y/Y, driven by increased spending by communication service providers (CSPs).
- In the first nine months of 2025, two vendors—Ciena and Nokia—gained more than one percentage point of market share.
- Other vendors that gained some market share included 1Finity, Adtran, Cisco, and Smartoptics.

