International Business Machines Corporation

Eric Lebrun

Pascal Francois

Jeffrey Robert Warren

Frederic Raimbault

Guy Platel

Alain Rey

Jean-jacques Chartreux

Anne Chabanet

Jeff Warren

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.

System of high availability synchronous bandwidth allocation over FDDI

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.

System for effective allocation of network-wide bandwidth

To solve the problem raised by the allocation of synchronous bandwidth on a FDDI segment when this allocation is done by a centralized Allocator in an interconnected LAN domain, a Third Party Requestor receives from Quality of Service Allocator all information that it needs to ask for bandwidth reservation on the FDDI segment. Following the Station Management standard, the Third Party Requestor is able to act on behalf of the FDDI station that will submit synchronous traffic and ask for bandwidth allocation to a Synchronous Bandwidth Allocator. According to the Synchronous Bandwidth Allocator decision, the Third Party Requestor will then answer to the Quality of Service Allocator which will grant or deny the allocation over the whole path.

System for network wide bandwidth allocation

Communication controller allowing communication between application programs running in at least one host computer and DTEs attached to a X25 packet switched network and communicating through virtual circuits (VC), the communication being provided through the X25 network and a Systems Network Architecture (SNA) network. The controller includes tables and logic for establishing predetermined SNA sessions between the application programs and the communication controller, and tables and logic for linking at least one virtual circuit on a predetermined SNA session. The controller further includes memory for storing a set of alternate session tables defining, for each of said established predetermined SNA sessions, a prioritized list of alternate backup sessions, logic for detecting the occurrence of one failure on one SNA session, and logic for switching the virtual circuits linked to said session being subject of a failure to one backup session defined in the corresponding alternate session table. The alternate sessions being pre-established, the virtual circuits can be immediately connected to one alternate session without requiring further delay. A quick end-user reconnection is then allowed.

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Saint Jeannet, France

Eric Lebrun