Network switch load balancing

Claim 3

The method of claim 1 wherein the switch attribute includes at least one of a state, the TTL value, the processor idle time, and the free connection.

Claim 4

The method of claim 2 wherein the free connection includes a number of available sessions corresponding to a connection priority.

Claim 5

The method of claim 1 wherein exchanging the messages comprises: selecting a destination switch from a peer table; determining the load information of a source switch; and sending an advertise message from the source switch to the selected destination switch, the advertise message containing the load information.

Claim 6

The method of claim 4 wherein the peer table contains a switch attribute of the destination switch.

Claim 7

The method of claim 5 wherein the switch attribute includes at least one of a state, a time-to-live (TTL) value, a processor idle time, and a free connection.

Claim 8

The method of claim 6 wherein the free connection includes a number of available sessions corresponding to a connection priority.

Claim 9

The method of claim 7 wherein selecting a destination switch comprises: selecting the destination switch if the state of the destination switch indicates the destination switch is in a normal state.

Claim 10

The method of claim 8 wherein determining the load information comprises: determining the processor idle time of the source switch; and determining the free connection of the source switch.

Claim 11

The method of claim 9 wherein determining the load information further comprises: determining the authentication data of the source switch; and computing the checksum of the authentication data.

Claim 12

The method of claim 9 wherein determining the processor idle time comprises: obtaining samples of task idle times based on a probabilistic distribution; and estimating an average of the samples of task idle times based on an autoregressive moving average model, the average corresponding to the processor idle time.

Claim 13

The method of claim 11 wherein the probabilistic distribution is a Poisson distribution.

Claim 14

The method of claim 11 wherein the autoregressive moving average model is an exponentially weighted moving average.

Claim 15

The method of claim 6 further comprises: updating the TTL value of the destination switch.

Claim 16

The method of claim 1 wherein selecting one of the switches comprises: computing the metric using the free connection and a percentage of the processor idle time for each switch, the free connection including a number of available sessions corresponding to a connection priority of the connection request.

Claim 17

The method of claim 15 wherein the selected one of the switches corresponds to a best metric of the computed metrics of the switches.

Claim 18

The method of claim 16 wherein the best metric is determined based on at least one of a predetermined local threshold, a redirection overhead, and a remote information reliability.

Claim 19

The method of claim 17 further comprises: accepting the connection request by the local switch if the metric of the local switch exceeds the predetermined local threshold.

Claim 20

The method of claim 18 further comprises: adjusting the metric of the one or more remote switches based on at least one of the redirection overhead and the remote information reliability; redirecting the connection request to one of the one or more remote switches if the adjusted metric of the one of the one or more remote switches is the highest metric and higher than the metric of the local switch; and accepting the connection request by the local switch if the metric of the local switch is higher than the highest adjusted metric of the one or more remote switches.

Claim 21

A computer program product comprising: a computer usable medium having computer program code embodied therein to balance load in a cluster of switches in a network, the switches including a local switch and one or more remote switches, the computer program product having: computer readable program code for exchanging messages among the switches, the messages including an advertise message sent at a refresh interval, the advertise message containing load information of the switches including at least one of a version number, a message type, the refresh interval, an authentication method, a source address, a public address, a checksum, a processor idle time, a free connection, and an authentication data, the computer readable program code for exchanging messages comprising: computer readable program code for receiving the advertise message from a source switch, the advertise message containing the load information of the source switch including a switch attribute, the computer readable program code for receiving the advertise message comprising: computer readable program code for listening on a broadcast port, computer readable program code for processing the advertise message to extract the switch attribute, and computer readable program code for storing the switch attribute in a peer table; and computer readable program code for selecting one of the switches in response to a connection request to the local switch based on a metric; wherein the computer readable program code for processing the advertise message comprises: computer readable program code for validating the checksum; computer readable program code for authenticating the advertise message using the authentication method and the authentication data; computer readable program code for validating the source address; computer readable program code for validating at least one of the version number, the message type, and the refresh interval; computer readable program code for setting a time-to-live (TTL) value using a predetermined maximum TTL value; and computer readable program code for extracting the switch attribute.

Claim 22

A computer program product comprising: a computer usable medium having computer program code embodied therein to balance load in a cluster of switches in a network, the switches including a local switch and one or more remote switches, the computer program product having: computer readable program code for exchanging messages among the switches, the messages including an advertise message sent at a refresh interval, the advertise message containing load information of the switches including at least one of a version number, a message type, the refresh interval, an authentication method, a source address, a public address, a checksum, a processor idle time, a free connection, and an authentication data, the computer readable program code for exchanging messages comprising: computer readable program code for receiving the advertise message from a source switch, the advertise message containing the load information of the source switch including a switch attribute, the computer readable program code for receiving the advertise message comprising: computer readable program code for listening on a broadcast port, computer readable program code for processing the advertise message to extract the switch attribute, and computer readable program code for storing the switch attribute in a peer table; and computer readable program code for selecting one of the switches in response to a connection request to the local switch based on a metric; wherein the computer readable program code for processing the advertise message comprises: computer readable program code for validating the checksum; computer readable program code for authenticating the advertise message using the authentication method and the authentication data; computer readable program code for validating the source address; computer readable program code for validating at least one of the version number, the message type, and the refresh interval; computer readable program code for setting a time-to-live (TTL) value using a predetermined maximum TTL value; and computer readable program code for extracting the switch attribute.

Claim 23

The computer program product of claim 20 wherein the switch attribute includes at least one of a state, the TTL value, the processor idle time, and the free connection.

Claim 24

The computer program product of claim 21 wherein the free connection includes a number of available sessions corresponding to a connection priority.

Claim 25

The computer program product of claim 1 wherein computer readable program code for exchanging messages comprises: computer readable program code for selecting a destination switch from a peer table; computer readable program code for determining the load information of a source switch; and computer readable program code for sending an advertise message from the source switch to the selected destination switch, the advertise message containing the load information.

Claim 26

The computer program product of claim 23 wherein the peer table contains a switch attribute of the destination switch. 25 .The computer program product of claim 24 wherein the switch attribute includes at least one of a state, a time-to-live (TTL), value, a processor idle time, and a free connection.

Claim 27

The computer program product of claim 25 wherein the free connection includes a number of available sessions corresponding to a connection priority.

Claim 28

The computer program product of claim 26 wherein the computer readable program code for selecting the destination switch comprises: computer readable program code for selecting the destination switch if the state of the destination switch indicates the destination switch is in a normal state.

Claim 29

The computer program product of claim 27 wherein the computer readable program code for determining the load information comprises: computer readable program code for determining the processor idle time of the source switch; and computer readable program code for determining the free connection of the source switch.

Claim 30

The computer program product of claim 28 wherein the computer readable program code for determining the load information further comprises: computer readable program code for determining the authentication data of the source switch; and computer readable program code for computing the checksum of the authentication data.

Claim 31

The computer program product of claim 28 wherein the computer readable program code for determining the processor idle time comprises: computer readable program code for obtaining samples of task idle times based on a probabilistic distribution; and computer readable program code for estimating an average of the samples of task idle times based on an autoregressive moving average model, the average corresponding to the processor idle time.

Claim 32

The computer program product of claim 30 wherein the probabilistic distribution is a Poisson distribution.

Claim 33

The computer program product of claim 30 wherein the autoregressive moving average model is an exponentially weighted moving average.

Claim 34

The computer program product of claim 25 further comprises: computer readable program code for updating the TTL value of the destination switch.

Claim 35

The computer program product of claim 20 wherein the computer readable program code for selecting one of the switches comprises: computer readable program code for computing the metric using the free connection and a percentage of the processor idle time for each switch, the free connection including a number of available sessions corresponding to a connection priority of the connection request.

Claim 36

The computer program product of claim 34 wherein the selected one of the switches corresponds to a best metric of the computed metrics of the switches.

Claim 37

A computer data signal embodied in a carrier wave comprising: a load balancing code segment to balance load in a cluster of switches in a network, the switches including a local switch and one or more remote switches, the load balancing code segment having: a message exchange code segment for exchanging messages among the switches, the messages including an advertise message sent at a refresh interval, the advertise message containing load information of the switches including at least one of a version number, a message type, the refresh interval, an authentication method, a source address, a public address, a checksum, a processor idle time, a free connection, and an authentication data, the message exchange code segment comprising: a receive code segment for receiving the advertise message from a source switch, the advertise message containing the load information of the source switch, including a switch attribute, the receive code segment comprising: a listening code segment for listening on a broadcast port, and a processing code segment for processing the advertise message to extract the switch attribute, and a store code segment for storing the switch attribute in a peer table; and a switch selecting code segment for selecting one of the switches in response to a connection request to the local switch based on a metric; wherein the processing code segment comprises: a first validation code segment for validating the checksum; a first authentication code segment for authenticating the advertise message using the authentication method and the authentication data; a second validation code segment for validating the source address; a third validation code segment for validating at least one of the version number, the message type, and the refresh interval; a setting code segment for setting a time-to-live (TTL) value using a predetermined maximum TTL value; and an extracting code segment for extracting the switch attribute.

Claim 38

A computer data signal embodied in a carrier wave comprising: a load balancing code segment to balance load in a cluster of switches in a network, the switches including a local switch and one or more remote switches, the load balancing code segment having: a message exchange code segment for exchanging messages among the switches, the messages including an advertise message sent at a refresh interval, the advertise message containing load information of the switches including at least one of a version number, a message type, the refresh interval, an authentication method, a source address, a public address, a checksum, a processor idle time, a free connection, and an authentication data, the message exchange code segment comprising: a receive code segment for receiving the advertise message from a source switch, the advertise message containing the load information of the source switch, including a switch attribute, the receive code segment comprising: a listening code segment for listening on a broadcast port, and a processing code segment for processing the advertise message to extract the switch attribute, and a store code segment for storing the switch attribute in a peer table; and a switch selecting code segment for selecting one of the switches in response to a connection request to the local switch based on a metric; wherein the processing code segment comprises: a first validation code segment for validating the checksum; a first authentication code segment for authenticating the advertise message using the authentication method and the authentication data; a second validation code segment for validating the source address; a third validation code segment for validating at least one of the version number, the message type, and the refresh interval; a setting code segment for setting a time-to-live (TTL) value using a predetermined maximum TTL value; and an extracting code segment for extracting the switch attribute.

Claim 39

The computer data signal of claim 36 wherein the switch attribute includes at least one of a state, the TTL value, the processor idle time, and the free connection.

Claim 40

The computer data signal of claim 37 wherein the free connection includes a number of available sessions corresponding to a connection priority.

Claim 41

The computer data signal of claim 36 wherein the message exchange code segment comprises: a peer code segment for selecting a destination switch from a peer table; a load code segment for determining the load information of a source switch; and a sender code segment for sending an advertise message from the source switch to the selected destination switch, the advertise message containing the load information.

Claim 42

The computer data signal of claim 39 wherein the peer table contains a switch attribute of the destination switch.

Claim 43

The computer data signal of claim 40 wherein the switch attribute includes at least one of a state, a time-to-live (TTL) value, a processor idle time, and a free connection.

Claim 44

The computer data signal of claim 41 wherein the free connection includes a number of available sessions corresponding to a connection priority.

Claim 45

The computer data signal of claim 42 wherein the peer code segment comprises: a destination code segment for selecting the destination switch if the state of the destination switch indicates the destination switch is in a normal state.

Claim 46

The computer data signal of claim 43 wherein the load code segment comprises: an idle code segment for determining the processor idle time of the source switch; and a connection code segment for determining the free connection of the source switch.

Claim 47

The computer data signal of claim 44 wherein the load code segment further comprises: a second authentication code segment for determining the authentication data of the source switch; and a checksum code segment for computing the checksum of the authentication data.

Claim 48

The computer data signal of claim 44 wherein the idle code segment comprises: a sampling code segment for obtaining samples of task idle times based on a probabilistic distribution; and an averaging code segment for estimating an average of the samples of task idle times based on an autoregressive moving average model, the average corresponding to the processor idle time.

Claim 49

The computer data signal of claim 46 wherein the probabilistic distribution is a Poisson distribution.

Claim 50

The computer data signal of claim 46 wherein the autoregressive moving average model is an exponentially weighted moving average.

Claim 51

The computer data signal of claim 41 further comprises: an update code segment for updating the TTL value of the destination switch.

Claim 52

The computer data signal of claim 36 wherein the switch selecting code segment comprises: a metric code segment for computing the metric using the free connection and a percentage of the processor idle time for each switch, the free connection including a number of available sessions corresponding to a connection priority of the connection request.

Claim 53

The computer data signal of claim 50 wherein the selected one of the switches corresponds to a best metric of the computed metrics of the switches.

Claim 54

The apparatus of claim 1 wherein a switch selector comprises: a metric generator to compute the metric using the free connection and a percentage of the processor idle time for each switch, the free connection including a number of available sessions corresponding to a connection priority of the connection request, the metric generator generating a local metric corresponding to the local switch and one or more remote metrics corresponding to the one or more remote switches.

Claim 55

The apparatus of claim 52 wherein the selected one of the switches corresponds to a best metric of the computed metrics of the switches.

Claim 56

The apparatus of claim 53 wherein the best metric is determined based on at least one of a predetermined local threshold, a redirection overhead, and a remote information reliability.

Claim 57

The apparatus of claim 54 further comprises: a local comparator to compare the metric of the local switch and the predetermined local threshold, the local comparator generating a local result.

Claim 58

The apparatus of claim 55 further comprises: one or more metric adjusters coupled to the metric calculator to adjust the metric of the one or more remote switches based on at least one of the redirection overhead and the remote information reliability; a first metric comparator coupled to the one or more metric adjusters to compare the adjusted metrics of the one of the one or more remote switches, the metric comparator generating a highest adjusted metric from the adjusted metrics; a second metric comparator coupled to the first metric comparator and the metric calculator to compare the highest adjusted metric and the local metric, the second metric comparator generating a remote result; and a decision logic coupled to the local comparator and the metric comparator to generate a decision based on the local and remote results, the decision accepting the connection request by the local switch if the local metric is higher than the local threshold or is higher than the highest adjusted metric.