System and method for message routing in a network

• US 20050243817A1
• Filed: 04/30/2004
• Published: 11/03/2005
• Est. Priority Date: 04/30/2004
• Status: Active Grant

• Current Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Original Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Inventors: Gardner, Edward A., Helliwell, Richard Perham, Wrenn, Richard Fitzhugh
• Granted Patent: US 9,210,073 B2
• Time in Patent Office: Days
• US Class Current: 370/389
• CPC Class Codes: H04L 1/16 in which the return channel carries supervisory signals, e.g. repetition request signals
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 45/121 by minimising delays
• CPC Class Codes: H04L 45/22 Alternate routing
• CPC Class Codes: H04L 45/24 Multipath
• CPC Class Codes: H04L 45/28 using route fault recovery
• CPC Class Codes: H04L 45/302 Route determination based on requested QoS
• CPC Class Codes: H04L 47/25 with rate being modified by the source upon detecting a change of network conditions
• CPC Class Codes: H04L 67/10 in which an application is distributed across nodes in the network software deployment G06F8/60; multiprogramming arrangements G06F9/46
• CPC Class Codes: H04L 67/14 Session management for real-time applications in data packet communications networks H04L65/1066
• CPC Class Codes: H04L 67/63 Routing a service request depending on the request content or context
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]

Abstract

A system and method for message routing in a computer network. The present system establishes a routing layer between the network and transport layers in a network, for communicating routing information between end-points in the network. A route management connection for communicating route management information between two ports in the network is established between pseudo end-points in the network. A route and route set are established between end-points in the network, where the route set provides a relationship between two end-point incarnations that indicates the existence of at least one route between the end-points. A route set management connection is established between the end-points for managing connections that are established on the route set. A route between the end points is selected using a route in the route set, and an application connection is established between two applications running on respective end-points in the network, using the route set and the route set management connection.

Claims

1. A method for message routing in a network comprising the steps of:

establishing a route management connection, between pseudo end-points in the network, comprising a connection for communicating route management information between two ports in the network, wherein each of the pseudo end-points is a logical extension of a corresponding one of the ports;

sending end-point and port configuration information to other ports in the network via the route management connection;

establishing at least one route between end-points'"'"' in the network via the route management connection;

establishing a route set between the end-points, wherein the route set provides a relationship between two end-point incarnations that indicates the existence of at least one said route between the end-points and associates a plurality of routes between the end-points;

establishing a route set management connection, between the end-points, for managing connections established on the route set;

selecting, from the route set, a selected route for sending each transmission between the end points; and

establishing an application connection, between two applications running on respective end-points in the network, using the route set and the route set management connection.

2. The method of claim 1, wherein the route management information includes route registration messages and name server queries and responses.

3. The method of claim 1, wherein a plurality of the routes are grouped into the route set by performing the steps of:

using indicia of a newly-created route proxy'"'"'s remote end-point including UID and incarnation identifier to find a corresponding route set among existing route sets; and

grouping the new route proxy with other route proxies to the same said end-point by attempting to add the route proxy to the corresponding route set.

4. The method of claim 3, wherein:

if no corresponding route set presently exists, then the local end-point attempts to create a route set to the remote end-point described in the corresponding new route event;

if a new route set was successfully created, then the new route proxy is added to the new route set route set as its first member, otherwise the new route is refused; and

if the attempt to add the new route to the route set failed, the new route proxy is deleted and the new route is refused.

5. The method of claim 1, wherein data, opaque to the ports, is exchanged between the end-points via a full route registration protocol conducted by said ports.

6. The method of claim 5, wherein the route set management connection is established essentially simultaneously with establishment of the first route in the route set by passing information, opaque to the ports, including connection identifiers and protocol versions of the route set management connection.

7. The method of claim 5, wherein a local end-point describes to a remote end-point a local route index within the route set for the route being established, by passing the index as information that is opaque to the ports, wherein the index is used by the remote end-point to identify a described route in headers of subsequent messages sent on a particular said route set.

8. The method of claim 5, wherein occurrence of either a new route originator event or a new route responder event causes a new said route set to be created.

9. The method of claim 1, wherein each time one of the end-points reboots, its old end-point incarnation is destroyed and a new end-point incarnation is created, including a new incarnation identifier associated with the new end-point incarnation.

10. The method of claim 9, wherein the incarnation identifier is unique over all said end-point incarnations.

11. The method of claim 1, wherein the route set is considered failed when it has neither associated route proxies nor client connections associated therewith.

12. The method of claim 1, wherein the route set is deleted when the route set has clients but has no associated route proxies for a predetermined continuous period of time.

13. The method of claim 1, wherein the route set is deleted when the route set has route proxies but has no associated clients for a predetermined continuous period of time.

14. The method of claim 1, wherein, when one of the end-points has more than one said route set to a given destination end-point, then any other route sets that exist to other incarnations of that destination end-point are run down when the destination end-point successfully receives a response to a message sent on the route set management connection.

15. The method of claim 1, wherein:

each said end-point determines route order independently, using locally available information, and

each said end-point communicates the determined route order to a corresponding remote said end-point to select a next said route for transmission.

16. The method of claim 15, wherein, when a new route is added to the route set or removed from the route set, the route set'"'"'s said route order changes and a new route order is communicated by a message transmitted via the route set management connection.

17. The method of claim 15, wherein a route order report message is sent on the route set management connection to communicate the route set'"'"'s locally determined route order to the corresponding remote said end-point.

18. The method of claim 17, wherein the route order report is a one-way sequenced message including a count field indicating the number of routes in the associated route set and an array containing an ordered list of a sender'"'"'s remote route index values of the routes in the sender'"'"'s local route set route order, wherein the remote route index comprises indicia of a remote route proxy describing a given said route.

19. The method of claim 1, wherein the network comprises a plurality of communication layers including transport and network layers, and wherein each said route comprises two unidirectional half routes, the method further comprising the step of establishing a routing layer between the network and transport layers;

wherein the routing layer performs message routing using a routing header, included in each transmission, to monitor transmissions on each half route to determine the half route'"'"'s quality; and

wherein the routing layer provides monitoring information, placed in the routing header, for one said route of each said route set.

20. The method of claim 19, wherein the monitoring information in the routing header is used to select one of the routes of the route set for sending future transmissions.

21. The method of claim 20, wherein the rate of transmission of messages sent between two end-points via each outbound half route is controlled by performing the additional steps of:

computing, at the transmitting end-point, a current transmission rate for each half route between a receiving end-point and a transmitting end-point;

computing a transmission rate limit for each half route at the receiving end-point;

sending a value for the transmission rate limit to the transmitting end-point in a field of the routing header, via one of the inbound half routes; and

using the transmission rate limit to place an upper bound on a current transmission rate indicative of transmissions issued on the outbound half route, by comparing the current transmission rate against the value of the transmission rate limit, at the transmitting end-point, to determine whether any of the outbound half routes within the route set is acceptable for sending the transmission without imposition of a delay;

wherein the transmission is sent, without imposition of a delay, on one of the outbound half routes having a current transmission rate no greater than the transmission rate limit; and

wherein, when none of the routes of the route set is acceptable, no transmissions are sent on any of the outbound half routes of the route set.

22. The method of claim 21, wherein the transmission rate limit of an inbound half route is computed from data contained in the routing headers of messages received on routes in the inbound half route'"'"'s route set;

wherein the transmission rate limit is used to express the quality of a half route; and

wherein the ratio of transmission rate to transmission rate limit is used to determine route underutilization.

23. The method of claim 21, wherein the transmission rate limit is used to express half route quality indicative of a condition of the half route wherein said condition is selected from the group of conditions consisting of whether the half route is delivering transmissions promptly, whether the half route has lost recent transmissions, and whether the half route is experiencing delay.

24. The method of claim 1, wherein the selected route is selected based on a determination of whether it is an initial transmission or a retry transmission.

25. The method of claim 1, wherein the selected route is selected for initial transmission by performing steps including:

selecting the last route used in the route set if the last route is still acceptable and has been used for fewer than a predetermined number of consecutive transmissions;

otherwise, selecting the least utilized acceptable route from the route set if there is one least utilized acceptable route; and

selecting a route from a round-robin queue of least utilized acceptable routes starting with the last route used if there are more than one least utilized acceptable routes in the route set;

otherwise queueing route selection requests in a queue until one of the routes therein becomes acceptable.

26. The method of claim 25, wherein said route is acceptable when:

the corresponding outbound half route is enabled and in the active state;

the corresponding outbound half route'"'"'s transmission rate is below its transmission rate limit; and

the corresponding outbound half route'"'"'s local port has sufficient resources to send a transmission, including an available outbound sequence object which is used to describe a transmission to be sent.

27. The method of claim 26, wherein each said end-point determines route order independently using locally available information and communicates said route order to said end-point'"'"'s remote end-point for use in route selection, and wherein a route is selected for a retry transmission by performing steps including:

selecting the next acceptable route in said route order relative to the route used for the previous transmission, if there are any acceptable routes in the route set;

otherwise

queueing route selection requests in a queue until one of the routes therein becomes acceptable.

28. A method for controlling a rate of transmission of messages sent between two end-points in a network via a route comprising an outbound half route from a transmitting end-point to a receiving end-point, and an inbound half-route from the receiving end-point to the transmitting end-point, the method comprising the steps of:

computing, at the transmitting end-point, a current transmission rate for each half route between the receiving end-point and the transmitting end-point;

computing, at the receiving end-point, a transmission rate limit for each said half route from data contained in routing headers of messages received on routes in the inbound half route'"'"'s route set;

sending a value for the transmission rate limit to the transmitting end-point, via the inbound half route; and

using the transmission rate limit to place an upper bound on a current transmission rate indicative of transmissions issued on the outbound half route, by comparing the current transmission rate against the value of the transmission rate limit, at the transmitting end-point, to determine whether any of the outbound half routes within the route set is acceptable for sending the transmission without imposition of a delay;

wherein the transmission is sent, without imposition of a delay, on one of the outbound half routes having a current transmission rate no greater than the transmission rate limit; and

wherein, when none of the routes of the route set is acceptable, no transmissions are sent on any of the outbound half routes of the route set.

29. The method of claim 28, wherein the transmission rate limit is used to express half route quality indicative of a condition of the half route, wherein said condition is selected from the group of conditions consisting of whether the half route is delivering transmissions promptly, whether the half route has lost recent transmissions, and whether the half route is experiencing delay.

30. The method of claim 28, wherein the network comprises a plurality of communication layers including transport and network layers, the method further comprising the step of establishing a routing layer between the network and transport layers;

wherein the routing layer is used for communicating the transmission rate limit for each half route from the receiving end-point to the transmitting end-point.

31. The method of claim 30, wherein the transmission rate limit is communicated from the receiving end-point to the transmitting end-point in a routing header sent via the routing layer.

32. The method of claim 30, wherein, in response to the situation wherein the routing layer client indicates that an ACK response timeout occurred on a route, the outbound half route'"'"'s transmission rate limit is reduced.

33. The method of claim 32, wherein the outbound half route'"'"'s transmission rate limit is reduced by approximately one-half.

34. The method of claim 28, wherein the routes in the route set are described in round-robin order, except when the occurrence of a significant event is detected with respect to a specific said route, in which case the route is given increased priority for being described to the remote end-point;

wherein said significant event comprises an event selected from the group of events consisting of;

an ACK response timeout occurring on the specific route,

a situation wherein the outbound half route selected for an initial transmission differs from the last route that was used to send a transmission on the route set, and

a situation wherein the outbound half route selected for a retry transmission differs from the last route that was used to send a transmission on the route set.

35. The method of claim 34, wherein, in response to said ACK response timeout, a corresponding flag indicating the occurrence of a significant event is set.

36. A method for message routing in a network comprising the steps of:

establishing a route management connection, between pseudo end-points in the network, comprising a connection used to communicate route management information between two ports in the network, wherein each of the pseudo end-points is a logical extension of a corresponding one of the ports;

sending end-point and port configuration information to other ports in the network via the route management connection;

establishing a route between end-points in the network via the route management connection;

establishing a route set between the end-points, wherein the route set indicates a relationship between two end-point incarnations that indicates the existence of at least one said route between the end-points and associates a plurality of routes between the end-points; and

establishing a route set management connection, between the end-points, for managing routing layer connections established on the route set;

wherein each time one of the end-points reboots, its then-existing end-point incarnation is destroyed and a new end-point incarnation is created, including a new incarnation identifier associated with the new end-point incarnation.

37. The method of claim 36, wherein the incarnation identifier is unique over all said end-point incarnations.

38. The method of claim 36, wherein the route set is deleted when the route set has clients but has no associated route proxies for a predetermined continuous period of time.

39. The method of claim 36, wherein the route set is deleted when the route set has route proxies but has no associated clients for a predetermined continuous period of time.

40. The method of claim 36, wherein, when one of the end-points has more than one said route set to a given destination end-point, then any other route sets that exist to other incarnations of that destination end-point are run down when the destination end-point successfully receives a response to a message sent on the route set management connection.

41. A method for message routing in a network including a plurality of communication layers including transport and network layers, the method comprising the steps of:

establishing a routing layer, between the network and transport layers, for communicating routing information between end-points in the network;

establishing a route management connection, between pseudo end-points in the network, comprising a connection used to communicate route management information between two ports in the network, wherein each of the pseudo end-points is a logical extension of a corresponding one of the ports;

establishing a route between end-points in the network; and

establishing a route set between the end-points, wherein the route set provides a relationship between two end-point incarnations that indicates the existence of at least one said route between the end-points.

42. The method of claim 41, wherein, in each transmission sent on a route set, the routing layer provides monitoring information, placed in a routing header describing one said route of the route set to a remote end-point.

43. The method of claim 42, wherein the routes in the route set are described in round-robin order, except when the occurrence of a significant event is detected with respect to a specific said route, in which case the route is given increased priority for being described to the remote end-point;

wherein said significant event comprises an event selected from the group of events consisting of;

an ACK response timeout occurring on the specific route,

a situation wherein an outbound half route selected for an initial transmission differs from the last route that was used to send a transmission on the route set, and

a situation wherein the outbound half route selected for a retry transmission differs from the last route that was used to send a transmission on the route set.

44. The method of claim 43, wherein the rate of transmission of messages sent between the two end-points is controlled by performing the additional steps of:

computing, at a receiving end-point, a transmission rate limit for each half route from data contained in routing headers of messages received on routes in the inbound half route'"'"'s route set;

sending a value for the transmission rate limit to the transmitting end-point in a field of the routing header, via the inbound half route; and

using the transmission rate limit to place an upper bound on a current transmission rate indicative of transmissions issued on the outbound half route, by comparing the current transmission rate against the value of the transmission rate limit, at the transmitting end-point, to determine whether any of the outbound half routes within the route set is acceptable for sending the transmission without imposition of a delay;

wherein the transmission is sent, without imposition of a delay, on one of the outbound half routes having a current transmission rate no greater than the transmission rate limit; and

wherein, when none of the routes of the route set is acceptable, no transmissions are sent on any of the outbound half routes of the route set.

45. The method of claim 44, wherein the transmission rate limit is a function of half route quality information including data indicative of a condition of one of the half routes wherein said condition is selected from the group of conditions consisting of whether the half route is delivering transmissions promptly, whether the half route has lost recent transmissions, and whether the half route is experiencing delay.

46. The method of claim 44, wherein, in response to said ACK response timeout, the outbound half route'"'"'s transmission rate limit is reduced and a corresponding flag indicating the occurrence of a significant event is set.

47. The method of claim 46, wherein the outbound half route'"'"'s transmission rate limit is reduced by approximately one-half, in response to said ACK response timeout.

48. The method of claim 43, wherein, when the outbound half route selected for an initial transmission differs from the last route that was used to send a transmission on the route set, significant event flags are set for the selected route and for the route proxy of the last route that was used to send a transmission on the route set is updated to be the selected route;

wherein the route proxy describes the state of the route from a local end-point incarnation to a remote end-point incarnation; and

wherein the significant event flags are cleared when the corresponding route is described to the remote end-point.

49. The method of claim 43, wherein, when the outbound half route selected for a retry transmission differs from the last route that was used to send a transmission on the route set, a significant event flag is set for the route proxy of the last route that was used to send a transmission on the route set, and said route proxy for the last route is updated to be the selected route;

wherein the route proxy describes the state of a route from a local end-point incarnation to a remote end-point incarnation; and

wherein the significant event flags are cleared when the corresponding route is described to the remote end-point.

50. A system for message routing in a network including a plurality of ports and a plurality of end-points, wherein a first one of the end-points communicates with a second one of the end-points via respective said ports connected by a fabric, the system comprising:

a route management connection, between pseudo end-points in the network, for communicating route management information between two said ports in the network, wherein each of the pseudo end-points is a logical extension of a corresponding one of the ports;

a route set, between two of the end-points, comprising a relationship between two end-point incarnations corresponding to the two end-points that indicates the existence of at least one said route between the end-points and associates a plurality of routes between the end-points; and

a route set management connection, between the end-points, for managing routing layer connections established on the route set.

51. The system of claim 50, wherein an application connection is established between two applications running on respective end-points in the network, using the route set management connection.

52. The system of claim 50, wherein the route management information includes route registration messages and name server queries and responses.

53. The method of claim 50, wherein a plurality of the routes are grouped into the route set by performing the steps of:

using indicia of a newly-created route proxy'"'"'s remote end-point including UID and incarnation identifier to find a corresponding route set among existing route sets; and

grouping the new route proxy with other route proxies to the same said end-point by attempting to add the route proxy to the corresponding route set.

54. The method of claim 53, wherein:

if no corresponding route set presently exists, then the local end-point attempts to create a route set to the remote end-point described in the corresponding new route event;

if a new route set was successfully created, then the new route proxy is added to the new route set route set as its first member, otherwise the new route is refused; and

if the attempt to add the new route to the route set failed, the new route proxy is deleted and the new route is refused

55. The system of claim 50, wherein the route set management connection is established essentially simultaneously with establishment of the first route in the route set by passing information, opaque to the ports, including end-point information and a local route index to a remote end-point in the network, wherein the local route index is used by the remote end-point to identify a described route in headers of subsequent messages sent on a particular said route set.

56. The system of claim 54, wherein occurrence of either a new route originator or a new route responder event causes a new said route set to be created.

57. The system of claim 50, wherein each time one of the end-points reboots, its old end-point incarnation is destroyed and a new end-point incarnation is created, including a new incarnation identifier associated with the new end-point incarnation.

58. The system of claim 57, wherein the incarnation identifier is unique over all said end-point incarnations.

59. The system of claim 50, wherein the route set is deleted when the route set has clients but has no associated route proxies for a predetermined continuous period of time.

60. The system of claim 50, wherein, when one of the end-points has more than one said route set to a given destination end-point, then any other route sets that exist to other incarnations of that destination end-point are run down when the destination end-point successfully receives a response to a message sent on the route set management connection.

61. The system of claim 50, wherein:

each said end-point determines route order independently, using locally available information, and

each said end-point communicates the determined route order to a corresponding remote said end-point to select a next said route for transmission.

62. The system of claim 61, wherein, when a new route is added to the route set or removed from the route set, the route set'"'"'s said route order changes and a new route order is communicated by a message transmitted via the route set management connection.

63. The system of claim 61, further including a route order report message sent on the route set management connection to communicate the route set'"'"'s locally determined route order to the corresponding remote said end-point.

64. The system of claim 63, wherein the route order report is a one-way sequenced message including a count field indicating the number of routes in the associated route set and an array containing an ordered list of a sender'"'"'s remote route index values of the routes in the sender'"'"'s local route set route order, wherein the remote route index comprises indicia of a remote route proxy describing a given said route.

65. The system of claim 50, wherein the network comprises a plurality of communication layers including transport and network layers, wherein each said route comprises two unidirectional half routes, the system further comprising:

a routing layer between the network and transport layers; and

a routing header, included in each transmission, used by the routing layer to perform message routing, and to monitor transmissions on each half route to determine the half route'"'"'s quality; and

wherein the routing layer provides monitoring information, placed in the routing header, for one said route of each said route set.

66. The system of claim 65, wherein the monitoring information in the routing header is used to select one of the routes of the route set for sending future transmissions.

67. The system of claim 66, further including:

means for determining, at the transmitting end-point, a current transmission rate for each half route between the transmitting end-point and the receiving end-point; and

means for computing a transmission rate limit for each half route which is a function of half route quality information determined at the receiving end-point;

wherein the value for the transmission rate limit is sent, in the routing header, to the transmitting end-point via the inbound half route;

wherein the transmission rate limit is used to place an upper bound on a current transmission rate indicative of transmissions issued on the outbound half route, by comparing the computed value for the transmission rate against the value of the transmission rate limit, at the transmitting end-point, to determine whether any of the outbound half routes within the route set is acceptable for sending the transmission without imposition of a delay;

wherein the transmission is sent, without imposition of a delay, on one of the outbound half routes having a current transmission rate no greater than the transmission rate limit; and

wherein, when none of the routes of the route set is acceptable, no transmissions are sent on any of the outbound half routes of the route set.

68. The system of claim 67, wherein the transmission rate limit is a function of half route quality information including data indicative of a condition of one of the half routes wherein said condition is selected from the group of conditions consisting of whether the half route is delivering transmissions promptly, whether the half route has lost recent transmissions, and whether the half route is experiencing delay.

69. The system of claim 50, wherein the selected route is selected for initial transmission by:

selecting the last route used in the route set if the last route is still acceptable and has been used for fewer than a predetermined number of consecutive transmissions;

otherwise, selecting the least utilized acceptable route from the route set if there is one least utilized acceptable route; and

selecting a route from a round-robin queue of least utilized acceptable routes starting with the last route used if there are more than one least utilized acceptable routes in the route set;

otherwise queueing route selection requests in a queue until one of the routes therein becomes acceptable.

70. The system of claim 69, wherein said route is acceptable when:

the corresponding outbound half route is enabled and in the active state;

the corresponding outbound half route'"'"'s transmission rate is below its transmission rate limit; and

the corresponding outbound half route'"'"'s local port has sufficient resources to send a transmission, including an available outbound sequence object which is used to describe a transmission to be sent.

71. The system of claim 70, wherein each said end-point determines route order independently using locally available information and communicates said route order to said end-point'"'"'s remote end-point for use in route selection, and wherein a route is selected for a retry transmission by selecting the next acceptable route in said route order relative to the route used for the previous transmission, if there are any acceptable routes in the route set;

otherwise, queueing route selection requests in a queue until one of the routes therein becomes acceptable.

72. A system for controlling a rate of transmission of messages sent between two end-points in a network via a route comprising an outbound half route from a transmitting end-point to a receiving end-point, and an inbound half-route from the receiving end-point to the transmitting end-point, the system comprising:

means for determining, at the transmitting end-point, a current transmission rate between the transmitting end-point and the receiving end-point;

means for computing a transmission rate limit for each half route which is a function of half route quality information determined at the receiving end-point; and

a message header for storing a value for the transmission rate limit;

wherein the value for the transmission rate limit is sent, in the message header, to the transmitting end-point via the inbound half route;

wherein the transmission rate limit is used to place an upper bound on a current transmission rate indicative of transmissions issued on the outbound half route, by comparing the computed value for the transmission rate against the value of the transmission rate limit, at the transmitting end-point, to determine whether any of the outbound half routes within the route set is acceptable for sending the transmission without imposition of a delay;

wherein the transmission is sent, without imposition of a delay, on one of the outbound half routes having a current transmission rate no greater than the transmission rate limit; and

wherein, when none of the routes of the route set is acceptable, no transmissions are sent on any of the outbound half routes of the route set.

73. The system of claim 72, wherein the transmission rate limit is a function of half route quality information including data indicative of a condition of one of the half routes wherein said condition is selected from the group of conditions consisting of whether the half route is delivering transmissions promptly, whether the half route has lost recent transmissions, and whether the half route is experiencing delay.

74. The system of claim 72, wherein the network comprises a plurality of communication layers including transport and network layers, the system further comprising a routing layer between the network and transport layers;

wherein the routing layer is used for communicating the message header containing the transmission rate limit for each half route between the two end-points.

75. The system of claim 74, wherein the transmission rate limit for each half route is communicated from the receiving end-point to the transmitting end-point in a routing header sent via the routing layer.

76. The system of claim 74, wherein, in response to the situation wherein the routing layer client indicates that an ACK response timeout occurred on a route, the outbound half route'"'"'s transmission rate limit is reduced.

77. The method of claim 76, wherein the outbound half route'"'"'s transmission rate limit is reduced by approximately one-half, in response to said ACK response timeout.

78. The system of claim 72, wherein the routes in the route set are described in round-robin order, except when the occurrence of a significant event is detected with respect to a specific said route, in which case the route is given increased priority for being described to the remote end-point;

wherein said significant event comprises an event selected from the group of events consisting of;

an ACK response timeout occurring on the specific route,

a situation wherein the outbound half route selected for an initial transmission differs from the last route that was used to send a transmission on the route set, and

a situation wherein the outbound half route selected for a retry transmission differs from the last route that was used to send a transmission on the route set.

79. The system of claim 78, wherein, in response to said ACK response timeout, a corresponding flag indicating the occurrence of a significant event is set.

80. A system for message routing in a network comprising:

a route management connection, between pseudo end-points in the network, comprising a connection used to communicate route management information between two ports in the network, wherein each of the pseudo end-points is a logical extension of a corresponding one of the ports;

a route set between the end-points, wherein the route set indicates a relationship between two end-point incarnations that indicates the existence of at least one route between the end-points and associates a plurality of routes between the end-points; and

a route set management connection, between the end-points, for managing connections established on the route set;

wherein each time one of the end-points reboots, its then-existing end-point incarnation is destroyed and a new end-point incarnation is created, including a new incarnation identifier associated with the new end-point incarnation.

81. The system of claim 80, wherein the incarnation identifier is unique over all said end-point incarnations.

82. The system of claim 80, wherein the route set is deleted when the route set has clients but has no associated route proxies for a predetermined continuous period of time.

83. The system of claim 80, wherein, when one of the end-points has more than one said route set to a given destination end-point, then any other route sets that exist to other incarnations of that destination end-point are run down when the destination end-point successfully receives a response to a message sent on the route set management connection.

84. A system for message routing in a network including a plurality of communication layers including transport and network layers, the system comprising:

a routing layer, between the network and transport layers, for communicating routing information between end-points in the network;

a route management connection, between pseudo end-points in the network, comprising a connection used to communicate route management information between two ports in the network, wherein each of the pseudo end-points is a logical extension of a corresponding one of the ports; and

a route set between the end-points, wherein the route set provides a relationship between two end-point incarnations that indicates the existence of at least one said route between the end-points.

85. The system of claim 84, wherein, in each transmission sent on a route set, the routing layer provides monitoring information, placed in a routing header describing one said route of the route set to a remote end-point.

86. The system of claim 85, wherein the routes in the route set are described in round-robin order, except when the occurrence of a significant event is detected with respect to a specific said route, in which case the route is given increased priority for being described to the remote end-point;

wherein said significant event comprises an event selected from the group of events consisting of;

an ACK response timeout occurring on the specific route,

a situation wherein the outbound half route selected for an initial transmission differs from the last route that was used to send a transmission on the route set, and

a situation wherein the outbound half route selected for a retry transmission differs from the last route that was used to send a transmission on the route set.

87. The system of claim 86, wherein the rate of transmission of messages sent on each half route between the two end-points is controlled by:

computing a transmission rate limit for each half route at a receiving end-point;

sending a value for the transmission rate limit for each half route to the transmitting end-point in a field of the routing header, via the inbound half route; and

using the transmission rate limit to place an upper bound on a current transmission rate indicative of transmissions issued on the outbound half route, by comparing the computed value for the transmission rate against the value of the transmission rate limit, at the transmitting end-point, to determine whether any of the outbound half routes within the route set is acceptable for sending the transmission without imposition of a delay;

wherein the transmission is sent, without imposition of a delay, on one of the outbound half routes having a current transmission rate no greater than the transmission rate limit; and

wherein, when none of the routes of the route set is acceptable, no transmissions are sent on any of the outbound half routes of the route set.

88. The system of claim 87, wherein the transmission rate limit is a function of half route quality information including data indicative of a condition of one of the half routes wherein said condition is selected from the group of conditions consisting of whether the half route is delivering transmissions promptly, whether the half route has lost recent transmissions, and whether the half route is experiencing delay.

89. The system of claim 87, wherein, in response to said ACK response timeout, the outbound half route'"'"'s transmission rate limit is reduced and a corresponding flag indicating the occurrence of a significant event is set.

90. The method of claim 89, wherein the outbound half route'"'"'s transmission rate limit is reduced by approximately one-half, in response to said ACK response timeout.

91. The system of claim 86, wherein, when the outbound half route selected for an initial transmission differs from the last route that was used to send a transmission on the route set, significant event flags are set for the selected route and for the route proxy of the last route that was used to send a transmission on the route set is updated to be the selected route;

wherein the route proxy describes the state of the route from a local end-point incarnation to a remote end-point incarnation; and

wherein the significant event flags are cleared when the corresponding route is described to the remote end-point.

92. The system of claim 86, wherein, when the outbound half route selected for a retry transmission differs from the last route that was used to send a transmission on the route set, a significant event flag is set for the route proxy of the last route that was used to send a transmission on the route set, and said route proxy for the last route is updated to be the selected route;

wherein the route proxy describes the state of a route from a local end-point incarnation to a remote end-point incarnation; and

wherein the significant event flags are cleared when the corresponding route is described to the remote end-point.

93. A system for message routing in a network comprising:

means for establishing a route management connection, between pseudo end-points in the network, comprising a connection used to communicate route management information between two ports in the network, and wherein each of the pseudo end-points is a logical extension of a corresponding one of the ports;

means for establishing a route between end-points in the network;

means for establishing a route set between the end-points, wherein the route set provides a relationship between two end-point incarnations that indicates the existence of at least one said route between the end-points;

means for establishing a route set management connection, between the end-points, for managing connections established on the route set;

means for selecting, from the route set, a selected route between the end points; and

means for establishing an application connection, between two applications running on respective end-points in the network, using the route set and the route set management connection.