Secondly, it studies the embedded system-level methodology in Ptolemy project and makes use of the three design steps Ptolemy project advocated in the embedded system to guide the embedded firewall system implementation.

• 研究Ptolemy嵌入式系统级设计方法学，并遵循Ptolemy所提倡的嵌入式系统级设计流程指导并完成嵌入式防火墙系统的设计。