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UTILIZATION OF USER DATA PROTOCOL DATA IN PROVIDING ENHANCED CLIENT AVAILABILITY IN A CLIENT-SERVER ARCHITECTURE

IP.com Disclosure Number: IPCOM000009720D
Original Publication Date: 2000-Jan-01
Included in the Prior Art Database: 2002-Sep-12
Document File: 3 page(s) / 121K

Publishing Venue

Motorola

Related People

David Jesus Garcia: AUTHOR [+4]

Abstract

Enhanced client availability can be obtained in a client-server architecture utilizing User Datagram Protocol (UDP) as the communication protocol between the client and server. Without any hardware modifications, the client-server application can pm- vide enhanced client availability by utilizing UDP state information.

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M-LA Technical Developments

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UTILIZATION OF USER DATA PROTOCOL DATA IN

PROVIDING ENHANCED CLIENT AVAILABILITY IN A CLIENT-SERVER ARCHITECTURE

by David Jesus Garcia, James Morris Tooker,

David Stephen Saewerl and Jerry Shihkuo Tang

ABSTRACT

  Enhanced client availability can be obtained in a client-server architecture utilizing User Datagram Protocol (UDP) as the communication protocol between the client and server. Without any hardware modifications, the client-server application can pm- vide enhanced client availability by utilizing UDP state information.

THEORY OF OPERATION

  Figure 1 shows a flowchart representation of the algorithm. The first process in the algorithm is client initialization. During this process, the client sends an initialization request message to the server. Since UDP is used as the communication protocol between the client and server, the server receives UDP state information along with the client initial- ization request message. Included in the UDP state information is the client's port identifier and Internet Protocol (IP) address. The server can assign a client identifier to the client and store the <client identiti- er,poa number,IP address> tuple of information in a client state machine and use it to diagnose the cur- rent state of the client. The server will send an ini- tialization response message containing the assigned client identifier to the client.

  Once the client's initialization request message has been acknowledged by the server, the client will begin to send periodic heartbeat messages to the server. The periodicity of the heartbeat messages indicates the client's normal processing state. If ape- riodic@ in the heartbeat messages is detected by the server, the server will increment a heartbeat timeout counter for the client. If the heartbeat timeout counter is less than a predefined threshold for the maximum number of consecutive heartbeat time-

outs, the server will await a heartbeat message from the client. If none is sent, the heartbeat timeout counter will again be incremented. This process continues until the threshold for consecutive heart- beat timeouts is reached. Once reached, the server will a...