The increasing demand for more bandwidth and the increased application variety fuel the need for high performance network processors. A simple but highly repetitive task performed by such processors is packet processing. Typically, a network processor consists of a parallel processor core with a number of memory interfaces and special co-processors. Recently, distributed architectures are being utilized in the design of network processors. In such environments, a challenging problem is to allocate optimal bandwidth between different network processors(NPs) to achieve more performance. In this paper, the formulation and solution of an optimal bandwidth allocation strategy using queuing network for NP-based architectures at system level is proposed. The solution allocates optimal bandwidth between network processors in a grid-oriented environment. It encompasses a new formula based on the optimal capacity allocation concept in queuingnetwork. our simulation results show that the proposed solution is able to enhance the response time in NP-based architectures when compared to a same NP-based architectures without optimal bandwidth allocation.