University College London INDRA project

This quarter saw the first major change on our ARPANET-EPSS-RL convention in several years, with the introduction of a completely new release of the PDP-9 operating system. The SATNET activity came to a very rewarding finale. We were able to make a number of interesting User Level Experiments, using tools which had been developed in previous years. Most of Internetwork activity during the quarter was in paper studies. Of particular importance was the study of how best to provide Transnet File Transfer Facilities, and a study of the X.25 CCITT protocol. The simulation work produced two publications. The first was a study of Hop-to-Hop versus end-to-end acknowledgement; the second constrasted the case of positive and negative acknowledgement.