TSAT advanced network services and routing architecture

In this paper, we provide an overview of the Transformational Communications Satellite (TSAT) baseline routing architecture and illustrate how policy-based route filtering can be used to support special connectivity scenarios such as virtual private networks (VPNs), intradomain connectivity in the presence of backdoor links, and split autonomous system (split-AS) interconnection. The VPN scenario arises as a means to provide connectivity between geographically separate user networks, via TSAT, while allowing them to operate within the same routing domain. The split-AS problem arises when a mobile ad-hoc network that is initially connected via terrestrial wireless links separates into two or more networks that can no longer reach each other. The challenge is to provide connectivity to these networks via an external network, such as TSAT, when they are separated and revert back to the use of terrestrial wireless paths when the links are restored. In addition to describing how these advanced capabilities can be met by the TSAT routing architecture, we also investigate the related developments in the Internet Engineering Task Force (IETF), describe alternative solutions for meeting these connectivity requirements, and illustrate how they could be