The growth of the Internet in the last decade has made current networking applications immensely complex. Systems running such applications need special architectural support to meet the tight constraints of power and performance. This paper presents a case study of architecture exploration and optimization of an Application Specific Instruction set Processor (ASIP) for networking applications. The case study particularly focuses on the effects of instruction set customization for applications from different layers of the protocol stack. Using a state-of-the-art VLIW processor as the starting template, and Architecture Description Language (ADL) based architecture exploration tools, this case study suggests possible instruction set and architectural modifications that can speed-up some networking applications upto 6.8 times. Moreover, this paper also shows that there exist very few similarities between diverse networking applications. Our results suggest that, it is extremely difficult to have a common set of architectural features for efficient network protocol processing and, ASIPs with specialized instruction sets can become viable solutions for such an application domain