Communications System and Method for Load Management

• US 20080267064A1
• Filed: 05/25/2005
• Published: 10/30/2008
• Est. Priority Date: 06/04/2004
• Status: Active Grant

• Current Assignee: Ericsson AB (Telefonaktiebolaget LM Ericsson)
• Original Assignee: Ericsson AB (Telefonaktiebolaget LM Ericsson)
• Inventors: Broadhurst, Ian, Lumb, Anthony Peter, Stewart, Donald David
• Granted Patent: US 8,817,609 B2
• Time in Patent Office: Days
• US Class Current: 370/230
• CPC Class Codes: H04Q 2213/13034 A/D conversion, code compression/expansion
• CPC Class Codes: H04Q 2213/13106 Microprocessor, CPU
• CPC Class Codes: H04Q 2213/13166 Fault prevention
• CPC Class Codes: H04Q 2213/13196 Connection circuit/link/trunk/junction, bridge, router, gateway
• CPC Class Codes: H04Q 2213/13387 Call gapping
• CPC Class Codes: H04Q 2213/13389 LAN, internet
• CPC Class Codes: H04Q 3/0091 Congestion or overload control

Abstract

A communications system comprising a target node and at least one source node arranged for communication of messages there between; in which the target node comprises means for processing at least some of the messages received from the at least one source node and means for detecting the processing load of the target node; in which the target node comprises means for notifying the at least one source node when a specific processing load level has been reached or exceeded; and in which each source node comprises means for reducing, responsive to the notification, the rate at which messages are sent to the target node.

Claims

1-64. -64. (canceled)

65. A communications system comprising:

a source node configured to communicate messages with a target node;

the target node comprising;

processing logic configured to process at least some of the messages received from the source node;

load detection logic configured to detect a processing load of the target node;

load control logic configured to notify the source node when a predetermined processing load level has been reached or exceeded, and to instruct the source node to reject a portion of the messages received at the source node without forwarding the messages to the target node; and

the source node comprising;

message filtering logic configured to reduce a rate at which messages are sent to the target node responsive to receiving the instruction from the target node.

66. The communications system of claim 65 wherein the target node comprises a call server.

67. The communications system of claim 65 wherein the source node is configured to function as a media gateway.

68. The communications system of claim 65 wherein the target node is configured to communicate an overload message to the source node to instruct the source node to reject the portion of the messages.

69. The communications system of claim 65 wherein the target node is configured to communicate a Negative Acknowledgement (NAK) to the source node to instruct the source node to reject the portion of the messages.

70. The communications system of claim 69 wherein the target node is configured to receive an ‘

off-hook’

notification signaling message from the source node in association with a new call attempt.

71. The communications system of claim 70 wherein the target node is configured to respond to each off hook message from the source node with the NAK, and wherein the NAK includes a proportion of call attempts to be rejected by the source node when the system is in an overload state.

72. The communications system as claimed in claim 70 wherein the source node is configured to reject subsequent off-hook requests.

73. The communications system of claim 65 wherein the source node is configured to send messages of more than one type to the target node, and wherein the target node is configured to identify the type of message received, and send a notification to the source node responsive to identifying a new connection request.

74. The communications system of claim 65 wherein the messages are categorized as being one of a low priority message and a high priority message, and wherein the source node is configured to only reduce the rate of the low priority messages.

75. The communications system of claim 74 wherein the source node is configured to:

process the high priority messages using less restrictive filtering logic to increase the chance of the high priority messages being successfully sent to the target node.

76. The communications system of claim 65 wherein a subset of end users is guaranteed service when the system is overloaded.

77. The communications system of claim 65 wherein the source node is configured such that a message to an emergency service bypasses the message filtering logic.

78. The communications system of claim 65 wherein the message filtering logic is configured to decrease the rate at which messages are sent to the target node if the source node does not receive additional notifications for a predetermined time.

79. The communications system of claim 65 wherein the message filtering logic is configured to increase the rate at which messages are sent to the target node if the source node does not receive additional notifications for a predetermined time.

80. The communications system of claim 65 wherein the source node further comprises network termination equipment that provides media gateway functionality.

81. The communications system of claim 65 wherein the target node further comprises recording logic to record notification information sent to the source node.

82. The communications system of claim 65 wherein the target node is configured to communicate messages with one or more source nodes, and wherein the target node is configured to notify only those source nodes that send a message to the target node during a time period in which the processing load reaches or exceeds the predetermined processing load level.

83. The communications system of claim 82 wherein the target node is configured to notify any of the source nodes responsive to receiving another message from the one or more source nodes following an increase in the processing load.

84. The communications system of claim 82 wherein the target node is configured to notify any of the source nodes only once for a selected processing load level.

85. The communications system of claim 82 wherein the target node is configured to include a notification in one or more additional messages sent to the one or more source nodes independently of whether the processing load reaches or exceeds the predetermined processing load level.

86. The communications system of claim 82 wherein the target node is configured to notify one or more of the source nodes in periodic non-call related messages independently of whether the processing load reaches or exceeds the predetermined processing load level.

87. The communications system of claim 82 wherein the target node is configured to send another notification to those source nodes that have already received a previous notification if the processing load reaches or exceeds the predetermined processing load level, and an overload level has increased.

88. The communications system of claim 65 wherein the processing load comprises the rate at which messages are received from one or more source nodes.

89. The communications system of claim 88 wherein the received messages comprise new connection requests.

90. The communication system of claim 65 wherein the messages comprise Internet Protocol messages.

91. A method of controlling a load at a target node comprising:

receiving messages from a source node;

processing at least some of the received messages at a target node by;

detecting a processing load of the target node;

notifying the source node when the processing load reaches or exceeds a predefined processing load level; and

instructing the source node to reject a portion of messages received at the source node without passing the messages on to the target node; and

reducing, at the source node, a rate at which messages are sent to the target node responsive to the instruction.

92. The method of claim 91 wherein the target node is a call server.

93. The method of claim 91 wherein the source node is configured to function as a media gateway.

94. The method of claim 91 further comprising the target node communicating an overload message to the source node to instruct the source node to reject the portion of the messages.

95. The method of claim 91 further comprising the target node communicating an automatic Negative Acknowledgement (NAK) to the source node to instruct the source node to reject the portion of the messages.

96. The method of claim 95 further comprising the target node receiving an ‘

off-hook’

notification signaling message from the source node in association with a new call attempt.

97. The method of claim 96 further comprising the target node responding to the off hook message with the NAK, and wherein the NAK includes a portion of call attempts that are to be rejected by the source node when the system is in an overload state.

98. The method of claim 97 wherein the source node rejects subsequent off-hook requests.

99. The method of claim 91 wherein the source node is configured to send messages of more than one type to the target node, and further comprising the target node:

identifying a type of message received from the source node;

sending a notification to the source node responsive to identifying a new connection request.

100. The method of claim 99 further comprising:

characterizing the messages as one of a low priority message or a high priority message at the source node; and

reducing only the rate of the low priority messages at the source node.

101. The method as claimed in claim 100 further comprising processing the high priority messages using less restrictive logic to increase the chance of the high priority messages being successfully sent to the target node.

102. The method of claim 91 further comprising guaranteeing service to a subset of end users when the system is overloaded.

103. The method of claim 91 further comprising:

receiving, at the source node, a message to an emergency service; and

allowing the emergency message to bypass logic that reduces the rate at which messages are sent to the target node.

104. The method of claim 91 further comprising the source node decreasing the rate at which it sends messages to the target node if the source node does not receive additional notifications for a predetermined time.

105. The method of claim 91 further comprising the source node increasing the rate at which it sends messages to the target node if the source node does not receive additional notifications for a predetermined time.

106. The method of claim 91 the source node comprises network termination equipment that provides media gateway functionality.

107. The method of claim 91 further comprising recording information associated with notifying the source node.

108. The method of claim 91 wherein the target node is configured to communicate messages with one or more source nodes, and further comprising notifying only those source nodes that provide a message to the target node during a time period when the predetermined processing load has been reached or exceeded.

109. The method of claim 108 further comprising sending a new notification to the one or more of the source nodes responsive to receiving another message from any of the source nodes following an increase in the processing load.

110. The method of claim 108 further comprising the target node notifying any one of the source nodes only once for a selected processing load level.

111. The method of claim 108 further comprising the target node including a notification in every message sent to a source node independently of whether the processing load reaches or exceeds the predefined processing load level.

112. The method of claim 108 further comprising the target node notifying the one or more of the source nodes in periodic non-call related messages independently of whether the processing load reaches or exceeds the predefined processing load level.

113. The method of claim 108 further comprising the target node sending another notification to one or more source nodes that have already received a previous notification if the processing load reaches or exceeds the predefined processing load level, and the overload level has increased.

114. The method of claim 91 wherein detecting a processing load of the target node comprises detecting the rate at which messages are received from the source node.

115. The method of claim 114 wherein detecting the rate at which messages are received from the source node comprises detecting the rate at which new connection requests are received from the source node.

116. The method of claim 91 wherein the messages comprise Internet protocol messages.

117. A node for a communications system comprising:

processing logic configured to process messages received from a remote communication node;

load detection logic configured to detect a processing load; and

load control logic configured to notify the remote node when a predetermined processing load level has been reached or exceeded, and to instruct the remote node to reject a portion of the messages received at the remote node without forwarding the messages to the node.

118. The node of claim 117 wherein the node comprises a call server.

119. The node of claim 117 wherein the load control logic is configured to communicate one of a Negative Acknowledgement (NAK) and an overload message to the remote node to instruct the remote node to reject the portion of the messages.

120. A node for a communications system comprising:

processing logic configured to communicate messages with a remote communication node; and

message filtering logic configured to;

receive a notification from the remote node that a predetermined processing load level has been reached or exceeded; and

reduce a rate at which messages are sent to the remote node responsive to receiving an instruction from the remote node.

121. The node claim 120 wherein the node comprises a media gateway.

122. The node of claim 120 wherein the message filtering logic is configured to reduce the rate at which the messages are sent to the remote node responsive to receiving one of a Negative Acknowledgement (NAK) and an overload message from the remote node.

123. The node of claim 120 wherein the message filtering logic is configured to reduce the rate at which the messages are sent to the remote node by rejecting at least a portion of the messages received at the node without forwarding the messages to the remote node.