Node discovery involving multiple node enumerators

• US 7,870,247 B2
• Filed: 12/14/2005
• Issued: 01/11/2011
• Est. Priority Date: 09/30/2004
• Status: Expired due to Fees

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Sverrisson, Heimir Thor, Black, Richard John
• Primary Examiner(s): Srivastava; Vivek
• Assistant Examiner(s): KRISHNAN, VIVEK V
• Application Number:
  US11/302,726
• Publication Number:
  US 20060168276A1
• Time in Patent Office: 1,854 Days
• Field of Search: 709/224
• US Class Current: 709/224
• CPC Class Codes: H04L 41/12 Discovery or management of network topologies
• CPC Class Codes: H04L 67/60 Scheduling or organising the servicing of application requests, e.g. requests for application data transmissions using the analysis and optimisation of the required network resources admission control or resource allocation H04L47/70
• CPC Class Codes: H04L 69/40 for recovering from a failure of a protocol instance or entity, e.g. service redundancy protocols, protocol state redundancy or protocol service redirection management of faults, events, alarms or notifications in data switching networks H04L41/06
• CPC Class Codes: H04W 40/00 Communication routing or communication path finding

Abstract

A network node discovery method allows multiple enumerators to concurrently accept and interpret the same enumeration responses from responder nodes on a network. In this manner, the responder nodes do not have to issue individual responses for each enumerator. Each responder maintains a discovery state and one or more per-enumerator session states to manage when the responder should transmit enumeration responses. The enumeration, therefore, proceeds at a target network load, irrespective of the number of enumerators present, and completes in a short time by making efficient use of the network capacity available. Furthermore, an enumerator can determine that it need only wait for responses solicited by other enumerators, rather than requesting them, thereby reducing network traffic in the presence of many concurrently enumerating nodes.

Claims

1. A method of managing transmission of one or more enumeration responses by a network node to enumeration requests received from a plurality of enumerators in a computer network, the method comprising:

receiving an enumeration request from one of the plurality of enumerators;

maintaining a session state table by the network node having a session state record for each of the plurality of enumerators;

if the enumeration request does not include an acknowledgement of a previous enumeration response by the network node and if the session state record for each of the plurality of enumerators indicate that the plurality of enumerators have not acknowledged a previous enumeration response by the network node;

determining a probability an enumeration response will be sent by another network node in a timing round based on an estimate of a quantity of network nodes that have not sent an enumeration response;

determining whether an enumeration response is to be sent by the network node in the timing round based on the probability an enumeration response will be sent by another network node in the timing round, and, if the enumeration response is to be sent by the network node in the timing round, determining a time to send the enumeration response, and, sending the enumeration response at the determined time;

determining a count of network nodes that sent an enumeration response during the timing round;

updating the estimate of the quantity of networks nodes that have not sent an enumeration response based on the count of network that sent an enumeration response during the timing round;

receiving an acknowledgement of the one or more enumeration responses from one of the plurality of enumerators; and

transitioning the session state record associated with the enumerator to a new state, responsive to receipt of the acknowledgement from the enumerator, wherein the new state indicates that the network node has received an acknowledgement from the enumerator.

2. The method of claim 1 wherein the session state record includes a sequence identifier provided by a corresponding one of the plurality of enumerators.

3. The method of claim 1 wherein the session state record includes an active time value indicating a time at which a corresponding one of the plurality of enumerators last requested an enumeration response.

4. The method of claim 1 further comprising:

maintaining a retransmission counter to limit the one or more enumeration responses relative to a retransmission threshold; and

terminating transmission of the enumeration responses if the retransmission counter satisfies the retransmission threshold.

5. The method of claim 1 further comprising:

maintaining a discovery state that indicates whether the session states for the plurality of enumerators indicate that no further enumeration responses are to be sent.

6. The method of claim 1 further comprising:

maintaining a discovery state that indicates whether the plurality of enumerators have acknowledged a previous enumeration response by the network node.