Abstract: A system of high availablity synchronous bandwidth allocation comprising an FDDI segment to which are connected a first device for allocating synchronous bandwidth over the FDDI segment to any requesting device, and at least a second device for requesting synchronous bandwidth over the FDDI segment. The first device and a third device also connected to said FDDI segment, are capable of a exchanging information regarding the allocation of synchronous bandwidth to at least the second device, the third device can take over for the first device as synchronous bandwidth allocator, if the first device fails.

Abstract: To address Quality of Service (QoS) requirements in a domain of Local Area Networks(LANs) interconnected by at least one FDDI segment, network-wide bandwidth allocation is improved by a high availability Third Party Requestor (3PR) agent. The 3PR receives from the QoS Allocator all information that it needs to ask for bandwidth reservation on the FDDI segment. Following a Station Management standard, the 3PR is able to act on behalf of an FDDI station that will submit synchronous traffic and ask for bandwidth allocation to a Synchronous Bandwidth Allocator (SBA). According to the SBA decision, the 3PR will then answer to the network-centralized QoS Allocator which will grant or deny the allocation over the whole path within the LAN domain. If for some reason, the acting SBA function moves to another station, the 3PR at the new station will become active.