A gateway system is described for use as a gateway between a client device and a remote server. The client device may stream a data stream via the gateway system to the remote server for remote processing. The gateway system may receive the data stream and markers which identify respective blocks of packets in the data stream, wherein each identified block of packets is independently processable. In response to an instruction or configuration to effect a migration of the remote processing from the remote server to a further remote server, the gateway system may determine a block of packets in the data stream from which block of packets onwards the further remote server is to start processing the data stream so as to effect or initialize the migration, and when received, stream the determined block of packets and subsequent blocks of packets of the data stream to the further remote server.