ISO 21076:2016根据以下内容描述了SCCS架构: -空间通信所涉及的地面和空间所有关键要素的定义； -界定SCCS服务的概念； -对提供安全SCCS服务的系统元件和组件的要求； -每个元件类型的推荐协议栈配置；和 -推荐的端到端系统配置，以提供可互操作和可交叉支持的空间通信服务。 ISO 21076:2016未规定: -如何实施提供SCCS服务的系统的细节； -实现SCCS服务所需的显式技术； -应用或任务操作协议，但用于数据传输的协议除外； -飞行任务操作，但参与规划、安排和执行空间通信的操作除外；-航天器机载交叉支持，空间通信服务除外。 ISO 21076:2016包含对其他CCSDS技术工程和架构建议的引用，描述了如何设计、部署、组织和操作进行空间通信交叉支持的系统，以提供可互操作的SCCS服务。虽然本文档没有指定详细的内部实现方法（这是私事），但它确实推荐了特定的协议和协议栈、服务接口、元素行为和端到端架构。 本文档中引用的一些标准，尤其是与SSI相关的标准，仍在开发中。它们包含在这里，以便读者清楚地了解它们如何适应整体架构。本文档与协议相关的部分自由引用了开放系统互连（OSI）基本参考模型中定义的层（参考文献[4]）。体系结构描述文档（ADD）的第6.2小节（参考文献【D5】）包含了对OSI堆栈和与每一层相关联的功能的讨论。 单跳交叉支持的技术范围是在整个太阳系中提供数据链路层（第2层）数据通信服务，以支持空间任务用户，使用一个或多个空间机构的互操作基础设施。还可以提供数据链路层之上的服务，诸如CCSDS文件传送协议(CFDP)、交叉支持文件服务(CXFS)或增量差分单向范围(DOR)。CCSDS中的所有任务操作应用程序-合规、可互操作的单跳部署有望利用这些底层空间链路和文件通信层。 SSI的技术范围是在整个太阳系提供互联（第3层）数据通信服务，以支持空间任务用户，利用一个或多个空间机构的联合和可互操作的基础设施来实现单个机构不太可能实现的服务水平。符合CCSDS的、可互操作的SSI部署中的所有任务操作应用程序都应利用这些底层空间互连通信层。 本文档的时间范围涵盖当前的单跳、安全的可互操作交叉支持安装、可互操作和不断发展的空间网络基础设施的未来部署，以及从当前部署发展到未来SSI状态的过渡策略。本次讨论包括任务驱动的考虑因素，例如使用混合科学/路由任务，以及确定被认为可接受的可选配置，因为它们符合本文件中定义的过渡策略。 任何希望作为对等方参与SSI的机构都应实现至少到网络层的可互操作服务和接口，以及相关支持服务，如本文所述以及相关CCSDS和互联网标准中所述。尚未准备好采用SSI，但希望提供能够支持SSI服务的合规地面站交叉支持服务的机构，也可以利用本文件作为开发数据链路层服务的指南，这些服务既能满足其当前需求，又能与支持SSI的任务互操作。

ISO 21076:2016 describes SCCS architecture in terms of the following: - definitions of all key elements, on ground and in space, that are involved in space communications; - definitions of concepts that characterize SCCS services; - requirements on system elements and components that provide secure SCCS services; - recommended protocol stack configurations for each element type; and - recommended end-to-end system configurations to provide interoperable and cross-supportable space communications services. ISO 21076:2016 does not specify: - the details of how to implement systems that provide SCCS services; - explicit technologies needed to implement SCCS services; - application or mission operations protocols except for those used for data transfer; - mission operations except for those involved in planning, scheduling, and executing space communications; - spacecraft onboard cross support, except for space communication services. ISO 21076:2016 contains references to other CCSDS technical engineering and architectural recommendations describing how systems doing space communication cross support should be engineered, deployed, organized, and operated to provide interoperable SCCS services. While this document does not specify detailed internal implementation approaches, which are a private matter, it does recommend specific protocols and protocol stacks, service interfaces, element behaviors, and end-to-end architectures. Some of the standards that are referenced in this document, especially those relating to the SSI, are still in development. They are included here so the reader gets a clear understanding of how they fit into an overall architecture. The protocol-related parts of this document make liberal reference to the layers defined in the Open Systems Interconnection (OSI) Basic Reference Model (reference [4]). Subsection 6.2 of the Architecture Description Document (ADD) (reference [D5]) contains a discussion of the OSI stack and the functions associated with each layer. The technical scope of single-hop cross support is the provision of Data Link Layer (Layer 2) data communications services across the Solar System in support of space mission users, using the interoperable infrastructure of one or more space agencies. Services above the Data Link Layer, such as CCSDS File Delivery Protocol (CFDP), Cross-Support File Service (CXFS), or Delta-Differential One-way Range (DOR), may also be provided. All mission operations application in CCSDS-compliant, interoperable, single-hop deployments are expected to utilize these underlying space link and file communications layers. The technical scope of the SSI is the provision of internetworked (Layer 3) data communications services across the Solar System in support of space mission users, using the confederated and interoperable infrastructure of one or more space agencies to achieve a level of service that individual agencies would otherwise be unlikely to achieve. All mission operations application in CCSDS-compliant, interoperable, SSI deployments are expected to utilize these underlying space internetworking communications layers. The temporal scope of this document covers current, single-hop, secure interoperable cross support installations, future deployments of an interoperable and evolving space networking infrastructure, and the transition strategies to evolve from current deployments to a future SSI state. Included in this discussion are mission-driven considerations, such as use of hybrid science/routing missions, as well as identification of optional configurations that are considered acceptable because they are in line with the transition strategies defined in this document. Any agency that wishes to participate as a peer in the SSI should implement interoperable services and interfaces at least up to the Network Layer, along with related support services, as described in this document and specified in the relevant CCSDS and Internet standards. Agencies that are not yet ready to adopt the SSI themselves, but that wish to offer compliant ground station cross support services that can support SSI services, may also take advantage of this document for guidance on developing Data Link Layer services that will both meet their immediate needs and also interoperate with SSI-enabled missions.