Some embodiments provide a method for a network slice selector that forwards messages from endpoint electronic devices onto different network slices of multiple network slices. The method receives a set of connection initiation messages setting up a connection between an endpoint electronic device and a network domain. The method forwards the set of connection initiation messages from the endpoint electronic device onto a default network slice while storing data regarding the connection initiation messages. After the connection is setup, the method receives a data message belonging to the connection from the endpoint electronic device. The method selects one of the plurality of network slices to which the electronic device has access as the network slice for the connection based on analysis of the received data message. The method retransmits the set of connection initiation messages on the selected network slice between the network slice selector and a network gateway.