1. A method for managing data transmission according to a Quality of Service (QoS) in a network assembly by a QoS architecture implemented in the network assembly, wherein the network assembly is provided with a plurality of host devices organized in a domain structure, each domain of the domain structure comprising a QoS managing device assigned to the domain, and wherein, being managed by the QoS architecture using for information exchange a signal protocol, the method comprising: for a proposed data transmission over the network assembly to a receiver host device, providing a resource request information with resource reservation parameters from a requesting host device to a receiving QoS managing device, in response to the resource request information, providing a response information from the receiving QoS managing device to the requesting host device, wherein the response information comprises one of a resource reservation information indicating a resource reservation and a failure reservation information indicating a failure to reserve the requested resource, if the resource reservation is made, maintaining the resource reservation by a maintaining mechanism implemented by the QoS architecture, and terminating the resource reservation after a termination is initiated by one of a termination information received by the receiving QoS managing device from the maintaining mechanism, a termination request provided by the requesting host device to the receiving QoS managing device, and a termination request provided by the receiving QoS managing device by itself, providing additional reservation parameters by the receiver host device, and adapting the reservation parameters after reception of the additional reservation parameters by one of the requesting host device and the receiving QoS managing device.