Method for wide area network service location

• US 6,446,108 B1
• Filed: 04/22/1998
• Issued: 09/03/2002
• Est. Priority Date: 07/18/1997
• Status: Expired due to Term

• Current Assignee: Nokia of America Corporation (Nokia Corporation)
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Rosenberg, Jonathan D., Schulzrinne, Henning G., Suter, Bernhard
• Primary Examiner(s): Barot, Bharat
• Application Number:
  US09/064,581
• Time in Patent Office: 1,595 Days
• Field of Search: 705/37, 705/14, 705/26-27, 709/200-203, 709/217-219, 709/227-229, 709/105-107, 709/231-233, 709/236-239, 709/245, 714/1, 707/1, 707/3, 707/9-10, 713/200-201
• US Class Current: 709/203
• CPC Class Codes: H04L 12/1854 with non-centralised forwarding system, e.g. chaincast
• CPC Class Codes: H04L 12/1886 with traffic restrictions for efficiency improvement, e.g. involving subnets or subdomains
• CPC Class Codes: H04L 61/00 Network arrangements, protocols or services for addressing or naming
• CPC Class Codes: H04L 61/45 Network directories; Name-to-address mapping

Abstract

A method for a client to locate a particular service from a service provider on wide area computer networks. The method includes multicasting of an advertisement from a service provider, which advertisement is detected by a Service Broker and in turn multicast into the wide area computer network. A client queries the network when seeking a particular service and receives in turn the address of the Broker and a Server to obtain the service desired.

Claims

1. A method for locating services in a wide area network, comprising the steps of:

receiving a communication from a Server X desiring to provide a service A to a client connected to said wide area network;

Server X joining a multicast group G1 on said wide area network, wherein Server X listens to said multicast group G1 and counts the number of other distinct servers which are currently sending advertisements for service A to said multicast group G1;

Server X periodically multicasting an advertisement for service A, wherein a period between sending of subsequent advertisements from Server X is dependent on the number of other distinct servers which are currently sending advertisements for service A to said multicast group G1;

storing, in a Broker Y'"'"'s database, the advertisement for service A multicast by Server X;

periodically multicasting from Broker Y an advertisement for service-A-Broker to multicast group G2;

processing a request from client C to Broker Y for a server providing service A; and

providing from Broker Y to client C an address for Server X to obtain service A.

2. A method for locating services in a wide area network in accordance with claim 1, further including the steps of:

storing, in a Directory Agent Z'"'"'s database, the advertisement multicast by Broker Y;

processing a communication from client C who is seeking a server for service A, and relaying said communication to Directory Agent Z;

initiating a database search by Directory Agent Z for providers of service-A-Broker;

locating Broker Y in response to said database search; and

returning an address for Broker Y to client C.

3. A method for locating services in a wide area network in accordance with claim 2, wherein said locating step further includes the steps of:

querying Broker Y on behalf of client C, and returning an address for Server X, provided by Broker Y, directly to client C.

4. A method for locating services in a wide area network in accordance with claim 1, further including the steps of:

registering, with a Notary, an advertisement generated by a server;

providing, by the Notary, authentication for the servers it represents; and

multicasting, by the Notary, the advertisements for the servers registered with the Notary.

5. A method for locating services in a wide area network, comprising the steps of:

defining a plurality of multicast addresses for services that can be provided in said wide area network;

Server X, desiring to provide a service A to a client connected to said wide area network, joining a multicast group G1 on said wide area network, wherein Server X listens to said multicast group G1 on the defined multicast address for service A and counts the number of other distinct servers which are currently sending advertisements for service A to said multicast group G1;

Server X periodically multicasting an advertisement for service A, wherein a period between sending of subsequent advertisements from Server X is dependent on the number of other distinct servers which are currently sending advertisements for service A to said multicast group G1;

storing, in a Broker Y'"'"'s database, the advertisement for service A multicast by Server X;

Broker Y periodically multicasting service announcements of advertisements it has stored in its database;

receiving and processing a request from client C to Broker Y for a server providing service A; and

providing from Broker Y to client C an address for Server X to obtain service A.

6. The method of claim 5, wherein the period between sending of subsequent advertisements from Server X further comprises:

said period is always greater than a pre-determined minimum period; and

said pre-determined minimum period increases with the age of the advertisement.

7. The method of claim 5, further comprising:

adding a random factor so that the actual period between sending of subsequent

advertisements varies randomly between ½ and

1½

times in length of the pre-determined minimum period.

8. The method of claim 5, further comprising:

Broker Y implementing at least one pre-determined policy to restrict which servers whose advertisements are kept in the Broker Y'"'"'s database.

9. The method of claim 5, further comprising:

Server X including in its service advertisements an attribute which indicates a value of the Time to live field used in the IP pockets containing the advertisement.

10. The method of claim 5, further comprising:

a client including a distance attribute in its service request to Broker Y, and specifying an allowable value for said distance attribute.