Several industry trends and new applications have brought the residential gateway router (RGR) to the center of digital home with direct connectivity to the service provider's network. Increasing risks of network attacks have necessitated the need for deep packet inspection in network processor (NP) used by RGR to match traffic at multiple gigabit throughput. Traditional deep packet inspection (DPI) implementations primarily focus on end hosts like servers, personal / handheld computers. Existing DPI signature matching techniques cannot be directly implemented in RGR due to various issues and challenges pertaining to processing capacity of the NP and associated memory constraints. So 4 key factors, regular expression support, gigabit throughput, scalability and ease of signature updates has been proposed through which best signature matching system could be designed for efficient DPI implementation in RGR.