A Proposal for RSVP over Differentiated Services Networks

Y. Shi and J.W. Atwood (Canada)


QoS, IntServ, DiffServ, RSVP, Bandwidth Broker, network backbone


Integrated Services (IntServ) provides per-flow QoS, which is suitable for dense access networks. End users ne gotiate their needs with the network using the Resource Reservation Protocol (RSVP). The IntServ/RSVP model, however, does not scale to many connections, which are present in backbone networks. Differentiated Services (DiffServ) assigns flows to classes, which are used to assign priority for packet handling in the backbone routers. How ever, DiffServ routers do not understand RSVP messages, and it is difficult to apply the IntServ-to-DiffServ mappings at each DiffServ router. The Bandwidth Broker (BB) was introduced to DiffServ domains, playing the role of admin istrator. However, the BB concept does not extend well to access networks. In this paper, we develop an architecture that permits retaining the advantages of IntServ in the ac cess networks, retaining the advantages of DiffServ in the backbone networks, and minimizing the changes that have to be made to existing DiffServ networks. The set of Diff Serv domains appear to the end user as a series of RSVP nodes, and the routers inside the DiffServ domains do not need to be aware of RSVP messages at all. In this way, the user's needs are met, without impacting the scalability of the backbone network.

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