An aspect of the present invention provides a method of controlling a multi-layer transport network. In accordance with the invention a determination is made as to whether a connection supporting a performance requirement of a call can be established within a first layer of the network. If the connection cannot be established, an association is defined between the call and a second call instantiated within a respective server layer of the network. By this means a network call controller in a client layer relies on a call and connection in a server layer instead of a connection in the client layer.