we consider a switched (queueing) network in which there are constraints on which queues may be served simultaneously; such networks have been used to effectively model input-queued switches, wireless networks and more recently data-centers. the scheduling policy for such a network specifies which queues to serve at any point in time, based on the current state or past history of the system. as the main result, we shall discuss a new class of online scheduling policies that achieve optimal scaling for average queue-size for a class of switched networks including input-queued switches. time permitting, we shall discuss various exciting open questions in the domain of stochastic networks. this is based on joint work with neil walton (univ of amsterdam) and yuan zhong (mit).