In this paper, we address the issue of how to improve performance of integrated optical path and optical packet. For supporting ultra-high-speed traffic, integration of optical paths and packets in a switch is one of key techniques in New Generation Networks. However, the wavelength allocation for optical packets and optical paths has not been efficiently resolved yet because there lacks of a systematic model for evaluating performance of the integrated switch. This paper models the operation of the integrated switch as a system of two servers, one for optical paths and the other for optical packets. From the model, we utilize Newton method to find an optimal policy for sharing of wavelength resources. Afterwards, we propose an algorithm to dynamically allocate wavelength resources in an integrated switch. Finally, we evaluate performance of that algorithm.