Verification of active nodes in an open network

• US 6,480,473 B1
• Filed: 12/29/1998
• Issued: 11/12/2002
• Est. Priority Date: 12/29/1998
• Status: Expired due to Fees

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Curry, Steven, Chambers, Paul
• Primary Examiner(s): Hsu, Alphus H.
• Assistant Examiner(s): Qureshi, Afsar M.
• Application Number:
  US09/222,402
• Time in Patent Office: 1,414 Days
• Field of Search: 370/252, 370/253, 370/254, 370/258, 370/346, 370/403, 370/449, 370/453, 370/454, 370/455, 370/456, 370/457, 370/450, 370/452, 709/220, 709/221, 709/251, 709/222, 709/224, 714/1, 714/2, 714/3, 714/4
• US Class Current: 370/253
• CPC Class Codes: H04L 41/00 Arrangements for maintenance, administration or management of data switching networks, e.g. of packet switching networks
• CPC Class Codes: H04L 45/02 Topology update or discovery

Abstract

The present invention involves a network polling protocol which treats the network as a logical ring or linear sequence of nodes linked together so that a polling request is simply propagated down or around the network one node at a time until a complete inventory of active nodes is achieved. The protocols also includes procedures for curing or repairing breaks in the linking protocol and for adding new nodes to the linking protocol. The linking protocol can also be used to establish hierarchal linked networks where top level hierarchies includes addresses to a permanent member of a linked network and bottom level hierarchies are a given linked network.

Claims

1. An information processing system (100;

110;

150) comprising a plurality of information processing nodes (102, 106;

112, 118;

154a-d;

200), wherein;

.

the nodes are functionally connected to form a network;

the system enables propagating a polling-token across the network;

the network is topologically configured as a directed graph for a purpose of propagating the polling-token;

each respective one of the nodes communicates (314) a polling-token along the network to a respective next one of the nodes;

each respective one of the nodes has a respective polling-timer (234);

the system initiates a reconfiguring (334) of the network if a specific one of the polling-timers expires before the polling-token is received.

2. The system of claim 1, wherein:

a specific one of the nodes associated with the expired specific polling-timer is enabled to propagate (602) a relink-token along the network;

each respective node receiving the relink-token is enabled to suspend (602) its respective polling-timer and is enabled to confirm receipt (604) of the relink-token to a preceding one of the nodes;

each respective node has a respective response-timer (236) for monitoring the confirmation;

each respective node is enabled to suspend (614) the respective response-timer upon receipt of the confirmation.

3.The system of claim 2, wherein;

the system enables a particular one of the nodes whose response timer expired to be linked to the specific node whose polling-timer expired.

3. The system of claim 1, wherein:

the system has first means (202, 204, 208, 210, 216, 218, 242) for determining a number of functionally active nodes on the network; and

the system has second means for controlling setting the respective polling-timers dependent on the number of nodes determined (202, 204, 216, 218).

4. The system of claim 4, wherein:

the polling-token is communicated from a current one of the nodes to the next node if the polling-timer of the current node expires;

the second means sets (900-914)the polling timers so that they expire at substantially evenly staggered moments in time in the order of the nodes along the directed graph.

5. A method of enabling operation of an information processing system (100;

110;

150) having a network with a plurality of information processing nodes (102, 106;

112, 118;

154a-d;

200), wherein the nodes are topologically interconnected to form a directed graph, the method comprising;

enabling each respective node to receive a polling-token from a respective preceding one of the nodes and to forward the polling-token to a respective succeeding one of the nodes;

enabling each respective one of the nodes to reset a respective polling-timer (234) upon receipt of the polling token;

enabling the system to initiate reconfiguring (334, 336, 700-720) the network upon expiry of a specific one of the respective polling-timers.

6. The method of claim 6, wherein each respective node has a respective response-timer (236) and wherein the reconfiguring comprises:

enabling a specific one of the nodes associated with the expired specific polling-timer to propagate (602) a relink-token along the graph;

enabling each respective node receiving the relink-token to suspend (602) its respective polling-timer and to confirm to a preceding one of the nodes receipt of the relink-token;

enabling each respective node to suspend (614) the respective response-timer upon receipt of the confirmation.

7. The method of claim 7 wherein the reconfiguring comprises:

enabling a particular one of the nodes whose response timer expired to be linked to the specific node whose polling timer expired.

8. A method of enabling operating an information processing system having a network with a plurality of information processing nodes (102, 106;

112, 118;

154a-d;

200), wherein the nodes are interconnected topologically to form a directed graph, the method comprising;

enabling each respective node to receive a polling-token from a respective preceding one of the nodes and to forward the polling-token to a respective succeeding one of the nodes;

enabling each respective one of the nodes to reset a respective polling-timer (234) upon receipt of the polling token;

enabling determining a number (CV) of functionally active nodes on the network; and

enabling controlling (900-914) the respective polling-timers dependent on the number of nodes determined.

9. The method of claim 9, wherein the controlling comprises setting the polling timers so that they expire at substantially evenly staggered moments in time in the order along the directed graph.

10. A method of functionally uniting a first and a second network (724a, 724b), wherein:

the first network has a first plurality of information processing nodes (C0-S0) configured in a first directed graph for a purpose of propagating a first polling-token across the first network;

the second network has a second plurality of information processing nodes (C1-S1) configured in a second directed graph for a purpose of propagating a second polling-token across the second network;

the method comprising;

enabling a first node in the first network to communicate (700) a message to the second network when in possession of the first polling-token; and

enabling a second node in the second network to respond to the message when in possession of the second polling-token,

enabling a third node succeeding the first node in the first network to become (716) a succeeding node to the second node in the second network; and

enabling a fourth node succeeding the second node in the second network to become (716) the successor of the first node.

11. For use in an information processing network (100, 110, 150) forming a directed graph for a purpose of propagating a polling token across the network:

an information processing node (200) comprising;

an input (230) for receipt of the polling token;

an output (232) for dispatch of the polling token;

a memory (204;

238-240) for storage of first and second addresses;

a timer (234) for monitoring a time period between dispatch and receipt of the polling token;

means for, under control of the timer, either dispatching a further polling token or sending relink message containing the first and second addresses.