Abstract: The hugely successful architecture and protocols of internet operate poorly when faced with operating environments such as long delays, excessive loss, network partitioning, or short node lifetime. Such problems are typically found in extreme space environments which lack infrastructure or under severe constraints such as limited power. This paper primarily addresses characteristics of space communication network on the base of quantitative analysis, brief synthesis is performed for Consultative Committee for Space Data System(CCSDS) Space Communications Protocol Specification(SCPS), and a model accounting for data security problem of space-earth all-in-one networking is provided.