Veiga, Pedro Manuel BarbosaSofia, Rute2009-02-102014-11-142009-02-102014-11-142004-12http://hdl.handle.net/10451/14299http://repositorio.ul.pt/handle/10455/3106Most Internet services require some form of differentiation, mainly because users rightly demand guarantees about the services they are subscribing to. Hence, these services usually rely on customer-provider agreements describing end-to-end Quality of Service requirements such as bandwidth level, or maximum delay, i.e., resource reservation requisites. To function properly, such agreements have to be enforced end-to-end, meaning that each router along the path has to keep information to manage the requested reservations. Current RSVP broad deployment is proof positive that a resource reservation protocol is necessary and useful to manage end-to-end resources. However, RSVP has severe scalability problems, which have already been investigated in RSVP enhanced versions. Still, new versions also fail when it comes to end-to-end scalability, and there is not a feasible alternative to RSVP. The scalability problem is mostly a consequence of the possible high reservation volumes that links between different Autonomous Systems may experience, and one way of dealing with this is to treat data based on aggregate reservations, since aggregation diminishes the state and signaling required at routers. In this dissertation, we analyse issues related to reservation aggregation. We introduce a novel aggregation protocol, SICAP, which performs shared-segment aggregation. We compare SICAP against the only other existing alternative, BGRP, which performs sink-tree aggregation, in terms of state scalability, signaling load, and bandwidth efficiencyporAggregationSignalingControlInter-domainReservationsBGRPdoctoral thesis