Real-time network routing

Claim 2

In a telecommunication network comprising a first and a second switching system and a plurality of third switching systems, a method of determining a route for a call between the first and second systems comprising the steps of: assembling first availability data of communication paths between said first system and ones of said third systems; assembling second availability data of communication paths between said second system and ones of said third systems; transmitting said second availability data from said second system to said first system; and determining a route between said first and said second systems via one of said third systems based on said first and said second availability data.

Claim 3

In a first telecommunications switching system, a method of determining a route between said first telecommunications switching system and a second telecommunications switching system over a telecommunications network comprising a plurality of third telecommunications switching systems, comprising the steps of: assembling first availability data of communication paths between said first system and ones of said third systems; receiving second availability data of communication paths between said second system and ones of said third systems; and determining a route between said first and said second systems via one of said third systems based on said first and said second availability data.

Claim 4

In a first telecommunications switching system, a method of determining a route between said first telecommunications switching system and a second telecommunications switching system over a telecommunications network comprising a plurality of third telecommunications switching systems, comprising the steps of: assembling first availability data of communication paths between said first system and ones of said third systems; receiving second availability data of communication paths between said second system and ones of said third systems; and determining a route between said first and said second systems via one of said third systems based on said first and said second availability data.

Claim 5

The method of claim 2 further comprising the step of: transmitting said second availability data from said second system to said first system.

Claim 7

The method of claim 4 wherein said step of selecting a route via a selected third system only having heavily loaded communication path groups in at least one of the groups comprises the step of selecting a route only if blocking between said first and said second systems is more than a predetermined threshold.

Claim 8

The method of claim 4 wherein said lightly loaded grade comprises a subgrade for very lightly loaded groups and a subgrade for moderately lightly loaded groups, wherein said very lightly loaded groups have a higher percentage of available communication paths than said moderately lightly loaded groups, and said step of selecting a route via a third system having lightly loaded groups comprises the step of: selecting a route via a third system having very lightly loaded communication path groups between that third system and said first and second systems in preference to a route via a third system in which at least one of the groups between that system and said first and second systems is moderately lightly loaded.

Claim 10

The method of claim 7 wherein said transmitting second availability data comprises the step of transmitting second availability data over a common channel signaling network.

Claim 11

The method of claim 7 wherein said step of transmitting second availability data comprises the step of transmitting said second availability data responsive to a request for said second availability data from said first system.

Claim 12

The method of claim 9 wherein said determining step is made responsive to availability data received in response to a previous request from said first system.

Claim 13

The method of claim 10 wherein said determining step comprises the step of requesting updated availability data from said second system for use in a subsequent determining step for a call between said first system and said second system.

Claim 14

The method of claim 7 comprising the step of transmitting said second availability data periodically.

Claim 16

The method of claim 13 wherein said plurality of grades comprises a reserved grade comprising communication path groups with paths available for calls, using two links, only if no other routes have available communication paths and if a high blocking rate between the first system and the second system has been encountered.

Claim 17

The method of claim 13 wherein said plurality of grades comprises a reserved grade comprising communication path groups with paths available for calls using two links only if no other routes have available paths in groups not in the reserved grade load status and if there is no direct route between the first system and the second system.

Claim 18

The method of claim 13 wherein a plurality of types of service are provided over a communication path group, wherein said plurality of grades comprises a reserved grade, and wherein the reserved grade of service is assignable to a subset of said plurality of types of service.

Claim 19

The method of claim 16 wherein said subset comprises services experiencing a high blocking rate between said first and said second system.

Claim 20

The method of claim 16 wherein said subset comprises services having fewer than a minimum desired number of calls completed.

Claim 21

The method of claim 4 wherein routes between switching systems comprise routes for transmitting different services requiring different transmission requirements, said routes having communication paths capable of transmitting for a plurality of different transmission requirements, wherein data for grades of availability are maintained for each transmission type, and wherein said determining step comprises the step of: determining availability data of communication paths capable of offering a requested transmission service.

Claim 22

The method of claim 4 wherein said first system further stores a list of third systems through which calls between said first and second systems are allowed to be routed, wherein the determining step comprises the step of: determining a route between said first and said systems via one of said third systems comprised in said list of third systems.

Claim 24

The method of claim 21 further comprising the steps of: before executing said determining step, testing whether a direct communication path between the first and the second system is available; and if the testing step indicates that no direct communication path is available, executing the determining step; and if the testing step indicates that a direct communication path is available, determining that the call is to be routed over the direct communication path.

Claim 25

In a first telecommunications switching system, apparatus for determining a route through a telecommunications network comprising: control means, comprising storage for a plurality of tables and a program, responsive to data stored in said plurality of tables, and operable under the control of said program for: responsive to an incoming call to said first system and to data stored in a translation table of said control means, determining that said call should be routed to a second switching system; assembling first availability data of first communication paths between said first system and ones of third switching systems connected to said first system by said first communication paths; receiving second availability data of communication paths and ones of said third systems; and determining a route between said first and said second systems via one of said third systems based on said first and said second availability data.

Claim 26

In a first telecommunications switching system, apparatus for determining a route through a telecommunications network comprising: control means, comprising storage for a plurality of tables and a program, responsive to data stored in said plurality of tables, and operable under the control of said program for: responsive to an incoming call to said first system and to data stored in a translation table of said control means, determining that said call should be routed to a second switching system; assembling first availability data of first communication paths between said first system and ones of third switching systems connected to said first system by said first communication paths; receiving second availability data of communication paths and ones of said third systems; and determining a route between said first and said second systems via one of said third systems based on said first and said second availability data.

Claim 27

The apparatus of claim 23 wherein said availability data comprises data indicating one of a plurality of grades of availability, including lightly loaded and heavily loaded grades of availability for communication path groups and wherein said determining a route comprises: selecting a route via a third system having lightly loaded communication path groups between said third system and said first and second systems; and if no routes are available via a third system having lightly loaded communication path groups between said third system and said first and second systems, selecting a route via a selected third system having heavily loaded communication path groups in at least one of the groups between said selected third system and said first and second systems.

Claim 28

The apparatus of claim 24 wherein selecting a route via a selected third system only having heavily loaded communication path groups in at least one of the groups comprises selecting a route only if blocking between said first and said second systems is more than a predetermined threshold.

Claim 29

The apparatus of claim 24 wherein said lightly loaded grade comprises a subgrade for very lightly loaded groups and a subgrade for moderately lightly loaded groups, wherein said very lightly loaded groups have a higher percentage of available communication paths than said moderately lightly loaded groups, and wherein selecting a route via a third system having lightly loaded groups comprises: selecting a route via a third system having very lightly loaded communication path groups between that third system and said first and second systems in preference to a route via a third system which at least one of the groups between that system and said first and second systems is moderately lightly loaded.

Claim 30

The apparatus of claim 23 wherein said control means is further operable under program control for preparing a data message for transmission to said second system for requesting said second availability data.

Claim 31

The apparatus of claim 27 wherein said determining is made responsive to availability data received in response to a previous request from said first system

Claim 32

The apparatus of claim 23 wherein said control means is further operable under program control for periodically preparing a data message comprising said first availability data for transmission to ones of said second and third systems.

Claim 33

The apparatus of claim 23 wherein said availability data specifies which of a plurality of bands, ranging from lightly loaded to heavily loaded to blocked, pertain to the availability of communication paths between a third system and said first or said second system, and wherein said determining comprises determining a route via a third system having communication path groups to said first and said second systems, the more heavily loaded of said groups to said first and said second systems having the least heavily loaded band of communication path availability.

Claim 34

The apparatus of claim 30 wherein said plurality of grades comprises a reserved grade comprising communication path groups with paths available for calls, using two links, only if no other routes have available circuits and if a high blocking rate between the first system and the second system has been encountered.

Claim 35

The apparatus of claim 30 wherein said plurality of grades comprises a reserved grade comprising communication path groups with paths available for calls using two links only if no other routes have available paths in groups not in the reserved grade load status and if there is no direct route between the first system and the second system.

Claim 36

The apparatus of claim 30 wherein a plurality of types of service are provided over a communication path group, wherein said plurality of grades comprises a reserved grade, and wherein the reserved grade of service is assignable to a subset of said plurality of types of service.

Claim 37

The apparatus of claim 33 wherein said subset comprises services experiencing a high blocking rate between said first and said second system.

Claim 38

The apparatus of claim 33 wherein said subset comprises services having fewer than a minimum desired number of calls completed.

Claim 39

The apparatus of claim 24 wherein routes between switching systems comprise routes for transmitting different services requiring different transmission requirements, said routes having a communication path capable of transmitting for a plurality of different transmission requirements, wherein data for grades of availability are maintained for each transmission type, and wherein said determining comprises determining availability data of communication paths capable of offering a requested transmission service.

Claim 40

The apparatus of claim 24 wherein said control means further comprises storage for a list of third systems through which calls between said first and second systems are allowed to be routed, wherein said determining step comprises: determining a route between said first and said second systems via one of said third systems comprised in said list of third systems.

Claim 41

The apparatus of claim 23 wherein said control means is further operable under program control for testing whether a direct communication path between the first and the second system is available; and if said testing indicates that no direct communication path is available, performing the determining a route via one of said third systems operation; and if said testing step indicates that a direct communication path is available, determining that the call is to be routed over the direct communication path.

Claim 42

39 . The method of claim 13 wherein said determining step selects among 2-link routes having the least heavily loaded of the more heavily loaded band for the route, that route having a link with the least heavily loaded band among said 2-link routes.

Claim 43

In a first telecommunications switching system, a method of determining a route between said first telecommunications switching system and a second telecommunications switching system over a telecommunications network comprising a plurality of third telecommunications switching systems, comprising the steps of: testing whether a direct communication path between the first and the second system is available; if the testing step indicates that a direct communication path is available, routing the call over the direct communication path; if the testing step indicates that no direct communication path is available, assembling first availability data of communication paths between said first system and ones of said third systems; transmitting a request for second availability data, of communication paths between said second system and ones of said third systems, to said second system; receiving, over a common channel signaling network, said second availability data; determining, in said first system, a route between said first and said second systems via one of said third systems based on said first and said second availability data; wherein said first and said second availability data comprise data indicating one of a plurality of grades of availability, including very lightly loaded, moderately lightly loaded, heavily loaded, and reserved grades of availability for communication path groups; wherein said determining step comprises the step of: selecting a route via a third system having very lightly loaded or moderately lightly loaded communication path groups between said third system and said first and second systems including selecting a route via a third system having very lightly loaded communication path groups between that third system and said first and second systems in preference to a route via a third system in which at least one of the groups between that system and said first and second systems is moderately lightly loaded; and if no routes are available via a third system having very lightly loaded or moderately lightly loaded communication path groups between said third system and said first and second systems, and if blocking between said first and said second systems is more than a predetermined threshold, selecting a route via a selected third system having heavily loaded communication path groups in at least one of the groups between said selected third system and said first and second systems; wherein said reserved grade comprises communication path groups with paths available for calls, using two links, for use in said determimng step only if no other routes have available communication paths and if there are no direct communication paths between said first and said second system and if a high blocking rate between the first system and the second system has been encountered; wherein a plurality of types of service are provided over a communication path group, and wherein the reserved grade of service is assignable to a subset, comprising services experiencing a high blocking rate between said first and said second system or having fewer than a minimum desired number of calls completed, of said plurality of types of service; wherein routes between switching systems comprise routes for transmitting different services requiring different transmission requirements, said routes having communication paths capable of transmitting for a plurality of different transmission requirements, wherein data for grades of availability are maintained for each transmission type, and wherein said determining step comprises the step of determining availability data of communication paths capable of offering a requested transmission service; wherein said first system further stores a list of third systems through which calls between said first and second systems are allowed to be routed, wherein the determining step comprises the step of determining a route between said first and said systems via one of said third systems comprised in said list of third systems.

Claim 44

In a first telecommunications switching system, a method of determining a route between said first telecommunications switching system and a second telecommunications switching system over a telecommunications network comprising a plurality of third telecommunications switching systems, comprising the steps of: testing whether a direct communication path between the first and the second system is available; if the testing step indicates that a direct communication path is available, routing the call over the direct communication path; if the testing step indicates that no direct communication path is available, assembling first availability data of communication paths between said first system and ones of said third systems; transmitting a request for second availability data, of communication paths between said second system and ones of said third systems, to said second system; receiving, over a common channel signaling network, said second availability data; determining, in said first system, a route between said first and said second systems via one of said third systems based on said first and said second availability data; wherein said first and said second availability data comprise data indicating one of a plurality of grades of availability, including very lightly loaded, moderately lightly loaded, heavily loaded, and reserved grades of availability for communication path groups; wherein said determining step comprises the step of: selecting a route via a third system having very lightly loaded or moderately lightly loaded communication path groups between said third system and said first and second systems including selecting a route via a third system having very lightly loaded communication path groups between that third system and said first and second systems in preference to a route via a third system in which at least one of the groups between that system and said first and second systems is moderately lightly loaded; and if no routes are available via a third system having very lightly loaded or moderately lightly loaded communication path groups between said third system and said first and second systems, and if blocking between said first and said second systems is more than a predetermined threshold, selecting a route via a selected third system having heavily loaded communication path groups in at least one of the groups between said selected third system and said first and second systems; wherein said reserved grade comprises communication path groups with paths available for calls, using two links, for use in said determimng step only if no other routes have available communication paths and if there are no direct communication paths between said first and said second system and if a high blocking rate between the first system and the second system has been encountered; wherein a plurality of types of service are provided over a communication path group, and wherein the reserved grade of service is assignable to a subset, comprising services experiencing a high blocking rate between said first and said second system or having fewer than a minimum desired number of calls completed, of said plurality of types of service; wherein routes between switching systems comprise routes for transmitting different services requiring different transmission requirements, said routes having communication paths capable of transmitting for a plurality of different transmission requirements, wherein data for grades of availability are maintained for each transmission type, and wherein said determining step comprises the step of determining availability data of communication paths capable of offering a requested transmission service; wherein said first system further stores a list of third systems through which calls between said first and second systems are allowed to be routed, wherein the determining step comprises the step of determining a route between said first and said systems via one of said third systems comprised in said list of third systems.

Claim 45

The method of claim 13 wherein the number of communication paths reserved is a function of the offered call load and the blockage rate.

Claim 46

The method of claim 41 wherein the number of communication paths reserved is zero if the offered call load is less than the current call load.

Claim 47

The method of claim 41 wherein the thresholds for the load bands of communication path groups are adjusted by the number of reserved communication paths.

Claim 48

The method of claim 14 wherein routes between switching systems comprise routes for transmitting different services requiring different transmission requirements, said routes having communication paths capable of transmitting for a plurality of different transmission requirements, and wherein communication paths are reserved for use for a particular transmission capability when the blocking for that capability exceeds a prespecified threshold.

Claim 49

The method of claim 44 wherein said communication paths are reserved for use for said particular transmission capability if the number of completed calls between the two switches connected by these communication paths and using said particular transmission capability is less than a prespecified threshold.

Claim 50

The method of claim 16 wherein the reserved grade is assignable to different ones of the plurality of types of service in response to blocking for the different ones exceeding a threshold individual to each different one.

Claim 51

The method of claim 16 wherein the reserved grade is assignable to different ones of the plurality of services if the number of completed calls between the two switches for ones of said plurality of services is less than a prespecified threshold.

Claim 52

The method of claim 13 wherein a threshold of each of said plurality of bands is a function of the offered call load.