The award flows through defense contractor Northrop Grumman, which assembled a team of companies to build network hubs supporting military operations worldwide.
Cisco's IP Video Conferencing 3540 Multipoint Control Unit for video conferencing and MeetingPlace for video, voice and Web conferencing will be the foundation of the system.
"[This contract] represents a significant validation of our overall intelligent information network strategy and affirms our position as a major player in video and rich media conferencing and collaboration," Charles Giancarlo, Cisco's chief development officer, said in a statement.
A Cisco spokeswoman declined to say how much revenue the San Jose, Calif., company expects from the project.
The DoD award is the second major video-related announcement from Cisco this month. Earlier, it said it would pay $6.9 billion for set-top box maker and video networker Scientific-Atlanta.