“Very competitive” is the best way to characterize the Optical Transport DWDM equipment market. While it is a sizeable market, weighing in at $15 billion, there are about 20 systems manufacturers that actively participate in selling DWDM equipment and aggressively vie for market share. . That said, 90 percent of the market is held by only seven vendors, leaving 10 percent for the remaining vendors, and even among the top seven, the market share delta is large—25 percentage points between the largest and smallest vendor.