A method for a computing system comprising: receiving, from a first media playback device connected to a first network, a first registration message ; in response to receiving the first registration message, assigning a system identifier and a first subsystem identifier to the first media playback device , wherein the system identifier is associated with the computing system , and wherein the first subsystem identifier is associated with the system identifier and the first network; receiving, from a second media playback device connected to a second network, a second registration message; determining, based on the second registration message, that the second media playback device is connected to the second network and assigning a second subsystem identifier to the second media playback device , wherein the second subsystem identifier is associated with the system identifier and the second network; transmitting, to the second media playback device , a message comprising the second subsystem identifier; receiving a request directed to devices associated with the second subsystem identifier; based on the request being directed to devices associated with the second subsystem identifier, causing the second media playback device to process the request; and in response to determining that the second media playback device is disconnected from the second network and connected to the first network, assigning the system identifier and the first subsystem identifier to the second media playback device , the first subsystem identifier associated with the system identifier and the first network, and transmitting, to the second media playback device , a message comprising the first subsystem identifier. receiving, from a first media playback device connected to a first network, a first registration message ; in response to receiving the first registration message, assigning a system identifier and a first subsystem identifier to the first media playback device , wherein the system identifier is associated with the computing system , and wherein the first subsystem identifier is associated with the system identifier and the first network; receiving, from a second media playback device connected to a second network, a second registration message; determining, based on the second registration message, that the second media playback device is connected to the second network and assigning a second subsystem identifier to the second media playback device , wherein the second subsystem identifier is associated with the system identifier and the second network; transmitting, to the second media playback device , a message comprising the second subsystem identifier; receiving a request directed to devices associated with the second subsystem identifier; based on the request being directed to devices associated with the second subsystem identifier, causing the second media playback device to process the request; and in response to determining that the second media playback device is disconnected from the second network and connected to the first network, assigning the system identifier and the first subsystem identifier to the second media playback device , the first subsystem identifier associated with the system identifier and the first network, and transmitting, to the second media playback device , a message comprising the first subsystem identifier. <EOS>