Real-time network routing

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 in said first system first present availability data of communication paths between said first system and ones of said third systems;
• receiving in said first system from said second system second present availability data of communication paths between said second system and ones of said third systems;
• and
• determining a route in said first system between said first and said second systems via one of said third systems based on said first and said second availability data.

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;
• 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 step comprises the step of:
• 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.

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;
• 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 step comprises the step of:
• 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.

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 lighly 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 determining 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 services 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.

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;
• 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;
• 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.

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;
• 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.

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 present 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 present availability data of communication paths and ones of said third systems;
• 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;
• and
• transmitting said first availability data to ones of said second and third systems for permitting each of said ones to determine a route between said each system and said first system.

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;
• 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 communcation paths between a third system and said first or said second system, and wherein said step of 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.

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;
• 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 step of 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.

A method of selecting an available telecommunications circuit for a service for a call to a destination in a system providing a plurality of services, wherein at least one of said plurality of services is a key service to be given preferential treatment, comprising the steps of:

• if the actual load for said service to said destination over a first choice circuit group is less than a predetermined objective and said service is a key service, selecting an available circuit of said first choice circuit group;
• and
• if the actual load for said service to said destination over a first choice circuit group is less than a predetermined objective, and said service is not a key service, selecting an available circuit of said first choice group only if the number of available circuits of said group exceeds a dynamically varying key reserve sum;
• if neither of the previous two steps causes an available circuit of said first choice group to be selected, selecting an available circuit of said first choice group only if the number of available circuits exceeds a dynamically varying total reserve sum.

In a first telecommunications switching system for serving a plurality of different service types of calls, apparatus for determining a group through a telecommunications network for a call having a given type of service, comprising:

• control means, comprising storage for a plurality of tables and a program, responsive to data stored in said plurality of tables;
• responsive to an incoming call to said first system and to data stored in a translation table of said control means, said control means operable under the control of a first portion of said program for determining that said call should be routed to a destination;
• said control means operable under the control of a second portion of said program for determining from said data a first choice circuit group for accessing said destination;
• said control means operable under the control of a third portion of said program for determining whether the actual load for said service to said destination is less than a predetermined objective, stored in said data, for said type of service and said destination;
• if said actual load is less than said objective, said control means operable under the control of a fourth portion of said program for selecting an available circuit of said first choice group, and if said actual load is equal to or greater than said objective, for selecting an available circuit of said first choice group only if the number of available circuits exceeds a dynamically varying total reserve sum.

A method of selecting an available telecommunications circuit for a service for a call to a destination in a system providing a plurality of services, wherein at least one of said plurality of services is a key service to be given preferential treatment, comprising the steps of:

• if the actual load for said service to said destination over a first choice circuit group is less than a predetermined objective and said service is a key service, selecting an available circuit of said first choice circuit group;
• and
• if the actual load for said service to said destination over a first choice circuit group is less than a predetermined objective, and said service is not a key service, selecting an available circuit of said first choice group only if the number of available circuits of said group exceeds a dynamically varying key reserve sum;
• if neither of the previous two steps causes an available circuit of said first choice group to be selected, selecting an available circuit of said first choice group only if the number of available circuits exceeds a dynamically varying total reserve sum;
• wherein said key reserve sum is the sum of circuits reserved for said group for all key services whose actual load is less than their predetermined objective load;
• wherein said total reserve sum is the sum of reserved circuits for all services whose actual load is less than the objective load of that service for said first choice circuit group, and wherein the number of circuits reserved for a service for said first choice circuit group is the difference between the objective and the actual load for that service, limited to a prespecified reserve limit;
• further comprising selecting a circuit from an alternate group if the actual load for said service equals or exceeds said objective for said load for said first choice group and the number of available circuits of said first choice group is equal to or less than said total reserve sum and the number of circuits available in said alternate group is greater than a total reserve sum for said alternate group;
• wherein if said first choice circuit group is connected to a switch that does not serve a specific destination, calls for one type of service to said specific destination are treated as calls for a different type of service, having its own predetermined objective, than calls for said one type of service to other destinations.