Recently, increasing attacks using network packets cause serious problems in networked environments ; from disturbing normal network operations to damaging computing resources. Among them denial of services are considered as critical attacks that directly exploit network packets to degrade availability. In this paper, we classify the types of denial of services in the network layer and develop detection methods that can keep the network from the classified denial of service attacks. The methods are then merged into an integrated denial of service detection algorithm that is scalable to detect new denial of service attacks.