In order to guarantee deadlines of real-time messages, it is necessary to construct connections or realtime channels before the actual transmission of the messages. An increasing number of distributed realtime systems that are related to multimedia and command and control systems require flexible network resource management. Those schemes proposed before couldn't accept channel construction request when there was not enough resource to meet the worst case requirement, because the attributes of those requests were statically fixed. In this paper, we propose a ffexible and efficient network management scheme. In our approach, it is assumed that the QoS requirement is specified as a range which covers from the value guaranteeing the minimum performance to the value guaranteeing the best performance. In the channel construction phase, we have adopted the fboding based approach in searching of the route from the source node to the destination node. And in the channel management phase, we have adopted elastic QoS model  and used both elastic coefficients and priorities to decide whether the existing channel should release or acquire the network resources, when the load conditions have changed due to changes in the QoS parameters of existent channel or arrival of new channel construction requests. Out approach realizes elastic QoS management for real-time communications which has not been supported yet.