The Defense Information Systems Agency (DISA) is conducting market research for full-spectrum engineering support of the Defense Information Systems Network (DISN), covering all elements, layers, and gateways. The support spans legacy, current, and future capabilities, with a key focus on IP/Optical Networking, Cloud Computing, and Access/Peering Gateways. The agency is seeking feedback from companies with proven expertise to deliver secure, reliable, and innovative engineering solutions. No specific performance location, budget amounts, or non-bid timelines are detailed in this description.