1. A non-transitory computer readable medium of a first computing device that participates in a communication session among a plurality of computing devices, the computer readable medium storing a computer program that is executable by at least one processing unit, the computer program comprising sets of instructions for: joining a first network that is established for routing a first type of media content data among the plurality of computing devices; through the first network, receiving media content data of the first type; from the received media content data of the first type, producing a first media presentation on the first computing device; joining a second network that has a different network topology than the first network and that is established for sharing a second type of media content data among the plurality of computing devices; through the second network, receiving media content data of the second type while concurrently receiving media content data of the first type through the first network; from the received media content data of the second type, producing a second media presentation on the first computing device, wherein the second network uses one of the computing devices as a central network hub for audio processing, wherein the audio processing includes accounting for silent participants.