Erling Kristiansen, European Space Agency, The Netherlands
Afonso Nunes, Skysoft Portugal, Portugal
José Brázio, Instituto de Telecomunicações, Portugal
André Zúquete, Instituto de Telecomunicações / IEETA, Portugal
We presented to ICSSC 2004 a paper entitled "Re-thinking the End-to-end Paradigm - The missing protocol layer". This paper described a novel architecture in which the TCP end-to-end transport in a heterogeneous network environment is split into a succession of separate transport instances, each operating over a homogeneous sub-network. This split architecture is augmented with a new end-to-end transport layer, inserted between the application layer and the split-transport layer. This new layer re-establishes the end-to-end context that was lost by the split. Since the presentation of that paper, it was realized that the introduction of changes to the protocol stack of all end systems, necessary in order to implement the new architecture, could be a major impediment to deployment of the system. An enhancement to the original architecture, now named SaNTA, is presented in this paper. In SaNTA, the new end-to-end layer is introduced between "satellite enhancer" (SE) entities located in association with the users’ Internet access routers rather than truly end-to-end. Support for network security has also been introduced into the SaNTA architecture. The SaNTA architecture has been implemented in a prototype that was tested both under controlled laboratory conditions and over a satellite link accessed through a WAN.