InterMedia is part of Faculty of Educational Sciences and located in Oslo Research Park, right opposite short end of IFI2 building, walking 100 meters in direction south-west.
More info: Google maps
You find the Infra room as follows: after entering InterMedia reception (pass two doors going straight through corner entrance of Research park), walk down corridor to the right about 15 meters. Room on your left, you see it as having three cubical windows facing the corridor.