With the rapid development of the Internet, for the benefit of improving the using rate of the entire network resources, the technique of inter-domain traffic engineering was proposed for the performance optimization of traffic that originates in one administrative domain and terminates in a different one. Based on the analysis and evaluation of current researches on the architecture of inter-domain traffic engineering, the RCP architecture for inter-domain traffic engineering was suggested. Finally, some main key problems were discussed for future researches.