In Metal Gear Solid, Solid Snake’s commanding officer who guides him by Codec is Roy Campbell.
Campbell is a retired United States Army colonel and the former commander of FOXHOUND. During the Shadow Moses crisis, he is brought back to coordinate Snake’s mission from the support team’s command center. His Codec calls provide objectives, tactical information, and mission updates.
Campbell is also connected personally to Meryl Silverburgh, who serves in the new FOXHOUND unit occupying Shadow Moses. That relationship is a major part of the story and explains Campbell’s concern for her safety. Players sometimes confuse Campbell with Master Miller, another adviser associated with Snake, but Miller is not the commanding officer directing the Shadow Moses operation. Campbell later appears in several other Metal Gear titles, although his role and circumstances change between games.