 Sense circuit for reading data stored in nonvolatile memory cells |
| There is a need for a sense circuit which although possessing static operating characteristics ... |
|
| Fault tolerant system employing majority voting |
| An object of the present invention is to provide a fault tolerant system which is able to select ... |
|
| High speed bus with virtual memory data transfer capability using virtual address/data lines |
| An improved high speed bus with virtual memory capability is disclosed. The bus has particular ... |
|
| Synchronizing two processors as an integral part of fault detection |
| What is claimed is: 1. A central processor unit including a fault detector means for detecting a ... |
|
| Byzantine resilient fault tolerant shared memory data processing system |
| What is claimed is: 1. A fault tolerant data processing system for providing single fault Byzantine ... |
|
| Protocol for interrupt bus arbitration in a multi-processor system |
| One object of the present invention is to provide for a multi-processor programmable interrupt ... |
|
| Multiprocessor computer backlane bus |
| OF THE PREFERRED EMBODIMENTS The following detailed description describes the logical, electrical, ... |
|
| Digital data processing methods and apparatus for fault detection and fault tolerance |
| The invention provides, in one aspect, a digital data processing device that includes a bus for ... |
|
|
Management of path routing in packet communications networks
| Details |
Inventors: Arrowood, Andrew Hilliard; Carriker, Jr., Charles A.; Magnuson, Anne Siegman; McClernan, Sharon Marie; Petri, Laura Marie; Temoshenko, Leo;
Assignee: International Business Machines Corporation (Armonk, NY)
Primary Examiner: Follansbee; John A.
Assistant Examiner:
Attorney, Agent or Firm: Woods; Gerald R., Timar; John J.
A packet communications network includes a route management system in which routes can be remotely changed by using a simple set command to set a data value in the originating or terminating node of the route. Storage tables in the originating and destination nodes record the route changes and administrative data concerning the route. This administrative data can be retrieved from the originating node by simple get or get-next commands. The administrative data can include the specific specification of the route in links, the time of creation of the route, the route replaced and the reason for initiating the change in route. Together these capabilities permit centralized management of route changes in the entire network from a single manager node, and using only simple set, get and get-next command structures. |
|
DETAILED DESCRIPTION In accordance with the illustrative embodiment of the present invention, a path management system is provided which provides central management of connection routing in systems having a limited protocol control command structure.
More particularly, a data object called a path object is defined as a read-write data value and is specified for each path originating at a particular node.
A table of such path objects, called the path table, is established in each Agent node of the network.
These data objects, which can be set to any desired value remotely by use of a "SET" command, are used to initiate the creation or deletion of data routes.
That is, each path data object is monitored by the local Agent node and, when a change in value is detected, a new path is generated, identified by the new value in the path data object.
Each path data object in the path table includes fields identifying the identification of the path, the route of the path, and administrative information such as, for example, the number of packets traveling in each direction on that path.
In further accord with the present invention, a path status data table is maintained at all of the Agent nodes which are end-points of path routes.
A new status entry in the path status table is created each time a route is deleted or modified.
Each status entry in the path status table contains a plurality of fields specifying the identification of the path, the time of establishment, the route of the old path, the route of the new path, the reason for the new path being created, and the result of the attempt to create the path, i.
e.
, success or failure.
A new entry is created in the path status table, not only when the centralized path Manager node directs the creation of a new path, but also when the new path is created in response to the Agent node's own path creation algorithms.
The Manager node, Agent node interactions are entirely independent of the supervisory control command structure used.
As suggested above, the SMNP management protocol can be used
|
|
Fault Detection 
