This paper proposes a queueing model including the control plane and the switching buffer mechanism of a GMPLS switch for evaluating the performance of a GMPLS switching architecture. With the proposed model, one can select appropriate parameters for the label-setup policy and the label-release policy to match the traffic load and network environment. Key performance metrics, including the throughput, the label-setup rate, and the fast path bandwidth utilization can be obtained via the analytical results. Numerical results and simulations are used to verify the accuracy of our proposed queueing model. The trade-off among these performance metrics can be observed as well.