Viavi Solutions operates two distinct businesses: network test equipment and optical specialty materials. The network and service enablement (NSE) segment, roughly 72% of revenue, makes test and measurement instruments used by telecom engineers, data center operators, and network equipment manufacturers to build, test, and maintain fiber and wireless networks. NSE products range from high-speed lab instruments (400G through 1.6-terabit) used by optical module makers and AI data center operators, to handheld field tools for fiber deployment, to 5G wireless test equipment sold to NEMs like Ericsson and Nokia. Viavi also sells software-based AIOps and network monitoring tools to telecom operators. A growing aerospace and defense sub-business sells avionics test equipment and positioning, navigation, and timing (PNT) solutions — hardware that helps military systems resist GPS jamming. The optical security and performance products (OSP) segment, roughly 28% of revenue, is built around Viavi's optical coating technology. OSP sells color-shifting anti-counterfeiting pigments used on banknotes in over 100 countries, distributed exclusively through a strategic alliance with SICPA, a dominant security ink company. OSP also makes precision optical filters used in consumer electronics depth-sensing cameras and automotive LiDAR systems. NSE revenue follows capital spending cycles at telecom providers and data center operators, while OSP profitability swings with factory utilization — incremental volume drops heavily to operating income. Viavi is actively diversifying away from telecom service provider exposure toward data center infrastructure and aerospace and defense, and recently acquired Inertial Labs and announced the acquisition of certain Spirent business lines to expand its portfolio.