US 6,389,024 B1Granted

Flexible call routing system

AssigneeExcel Switching Corporation

InventorsRajat Ghai, Mark P. Hebert, Michael Silva

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Abstract

The principle object of the present invention, is to provide flexibility in the routing functions performed in the switching system. Another object is to provide a router that can be centralized in a host computer or distributed among various switching nodes. The router is easily programmable by the system operator to provide different routing algorithms for various calls. The router can be used in a system with a single switching node. However, it is particularly adopted for use in a multiple-switching-node system, either as a central, host resident unit, or as a distributed router resident on the switching nodes. A router embodying the invention uses router tables that are readily configurable by the system operator to route calls based on predefined routing criterion in the incoming or outgoing call.

Claims15

Dependent claims

A communications network comprising:

(A) a plurality of switching nodes each of which contains line cards with multiple ports for connections between the communications network and subscriber lines or other switching systems, and objects for processing calls on channels associated with each port;
(B) an internal network interconnecting the switching nodes for conveying switched telecommunications data between them;
(C) a host computer that includes software applications which exercise supervisory control over the nodes;
(D) a host network linking the host computer with the switching nodes;
(E) a programmable router that utilizes a configurable routing table to route calls based on predefined routing criteria, said routing table including multiple entries each having multiple fields, a first field in each entry specifying one of a set of routing criteria, a second field in each entry specifying a group of ports to which a call may be routed and/or one or more of the other entries whose first fields are examined to determine whether call parameters match the criteria in those fields, and a field containing a route group identifier for indentifying entries having certain common criteria, and wherein said entries in said router table also include:
(i) a route number field for indexing the routing table;
(ii) a route property field for identifying a route type mask or range;
(iii) the first field which is a criterion type field for specifying one of a set of routing criteria types;
(iv) a criterion data length field for storing the length of routing criteria data and mask;
(v) a routing criteria data field for storing predefined routing criteria data;
(vi) a criterion data mask field for specifying which digits in the routing criteria data field to consider when routing a call;
(vii) a logical data count field for specifying the number of sets of logical data in the logical data field;
and
(viii) the second field which is a logical data field for storing sets of logical data which identify a call-termination channel group, said logical data field may also specify other entries in the routing table;
and
(F) means for logically combining values in routing table fields based on the results obtained by examining the other entries identified by the second field.

13 more elements

A switching node which comprises:

(A) line cards wit multiple ports for connections between switching node and subscriber lines or other switching systems;
(B) objects for processing call on channels associated with each port;
(C) a programmable router that utilizes a configurable routing table to route calls based on predefined routing criteria, said routing table including multiple entries each having multiple fields, a first field in each entry specifying one of a set of routing criteria, a second field in each entry specifying a group of ports to which a call may be routed and/or one or more of the other entries whose first fields are examined to determine whether call parameters match the criteria in those field, and wherein said entries in said router table also include:
(i) a route number field for indexing the routing table;
(ii) a route property field for identifying a route type mask or range;
(iii) the first field which is a criterion type field for specifying one of a set of routing criteria types;
(iv) a criterion data length field for storing the length of routing criteria data and mask;
(v) a routing criteria data field for storing predefined routing criteria data;
(vi) a Criterion data mask field for specifying which digits in the routing criteria data field to consider when routing a call;
(vii) a logical data count field for specifying the number of sets of logical data in the logical data field;
and
(viii) the second field which is a logical data field for storing sets of logical data which identify a call-termination channel group, said logical data field may also specify other entries in the routing table;
and s;
(D) means for logically combining values in routing table fields based on the results obtained by examining the other entries identified by the second field.

11 more elements

A method for routing calls in a communications network, the network comprising at least one switching node, said switching node comprising (a) line cards with multiple ports each of which has an associated channel and (b) a router that utilizes a configurable routing table to route calls based on predefined routing criteria, said routing table including multiple entries each having multiple fields, a first field in each entry specifying one of a set of routing criteria, a second field in eavh entry specifying a group of ports to which a call may be routed and/or one or more of the other entries whose first fields are examined to determine whether call parameters match the criteria in those fields, said method comprising the steps of:

(A) receiving incoming data in the channel from the associated line card port;
(B) sending the incoming data to the router;
(C) selecting each entry in the routing table to specifying:
(i) a route number field for indexing the routing table;
(ii) a route property field for identifying a route type mask or range;
(iii) a criterion type field for specifying one of a set of routing criteria types;
(iv) a criterion data length field for storing the length of routing criteria data and mask;
(v) a routing criteria data field for storing predefined routing criteria data;
(vi) a criterion data mask field for specifying which digits in the routing criteria data field to consider when routing a call;
(vii) a logical data field for storing sets of logical data which identify a call-termination channel group, said logical data field may also specify other entries in the routing table where a criterion tag is associated with criterion type in the incoming data;
(D) checking a criteria data field and a mask field in the selected entries to find the most specific value that fits the criterion data in the incoming data;
(E) selecting the entry that best matches the criterion data and checking a logic data count field to determine the number of logical data sets in a logical data field;
and
(F) checking a tag in each logical data set determine the group of ports to which a call may be routed and/or one or more of the other entries whose first fields are examined to determine whether call parameters match the criteria in those fields.

11 more elements

Dependencies are inferred from the claim text.