A robust IPUDPRTP header compression mechanism is provided to correctly reconstruct IPUDPRTP headers in the presence of packet losses and errors of unreliable networks. The method includes applying a suspension of an insulating coating to a refractory piece, drying the suspension, applying a glaze slip over the coating, and drying the slip to form a protective glaze. The produced inductors and transformers exhibit Q factors>60 at frequencies of 3 to 7 GHz.