# US 5,642,396 A · Release cause table for failed calls in SS7/ISDN Networks

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- Number: US 5,642,396 A
- Document ID: US5642396A
- Status: Granted
- Kind: A
- Application number: 08/438,934
- Filed: 1995-05-10
- Granted: 1997-06-24
- Earliest claimed: 1995-05-10
- Assignees: MCI, Inc.
- Inventors: George A. Cowgill
- Web page: https://patentgrep.com/patent/US5642396A

## CPC

- H04Q 3/0025: {Provisions for signalling}
- H04M 3/2254: {in networks}
- H04Q 3/66: Traffic distributors
- H04Q 11/0442: {Exchange access circuits}
- H04Q 2213/13103: Memory
- H04Q 2213/13172: Supervisory signals
- H04Q 2213/13176: Common channel signaling, CCS7
- H04Q 2213/13209: ISDN
- H04Q 2213/13349: Network management
- H04Q 2213/1338: Inter-exchange connection
- H04Q: SELECTING (switches, relays, selectors H01H; wireless communication networks H04W)
- H04M: TELEPHONIC COMMUNICATION (circuits for controlling other apparatus via a telephone cable and not involving telephone switching apparatus G08)

## Abstract

A plurality of release action tables are maintained in the switching nodes of a telecommunication network, e.g SS7, ISDN, one table for each trunk group. The table indicates desired actions or treatments to be taken for failed calls, each identified by a cause condition. Upon receiving a cause condition expressed as a code at a switching node, a release action table index is accessed to identify the release action table for the trunk group experiencing the cause condition. The cause code is compared against entries in the release action table by a control program included in the switching node. Based upon such comparison, the table indicates to the network the corrective action to be taken to remedy the failed call condition. Changes to the network for failed call conditions are accomplished by altering the data in the release action table rather than changing network.

## Claims

### Claim 1

In a telecommunications network including a plurality of switching nodes, a plurality of communication links, and a central control/diagnostic facility wherein said network includes means to propagate information backward along a call path in response to a network event, an improved method for processing failed calls at a switching node in response to network events comprising:
placing at said switching node at least one Release Action Table and a control program capable of utilizing said Release Action Table, wherein said Release Action Table indicates the appropriate action to be performed at said switching node as a result of a network event;
obtaining cause information at said switching node relating to said network event;
using said control program to compare said cause information against entries in said Release Action Table to locate a match;
reading from said Release Action Table corresponding action information relating to the appropriate action to take at said switching node in response to said network event; and
performing the action specified by said action information.

### Claim 2 (depends on 1)

The method for processing failed calls of claim 1 further comprising the step of generating a cause code to propagate backward along the call path, wherein said cause code is based jointly upon the information contained in said Release Action Table and said cause information corresponding to said network event.

### Claim 3

In a telecommunication network including a network control center, a plurality of interconnected switching nodes, each node having control programs, a system for managing failed call causes and automatically performing selected actions in response said failed cause condition, comprising:
a) a release action table installed in at least one switching node for at least one trunk group;
b) a release table index (Index) installed in at least one switching node for at least one trunk group;
c) means for obtaining cause conditions for failed calls on the network;
d) means for comparing said cause condition against entries in the release action table for a trunk group identified by the Index; and
e) means for correcting the cause condition based on an action specified in the release action table identified by the Index.

### Claim 4 (depends on 3)

The system of claim 3 wherein the switching node experiencing a cause condition takes corrective action on a failed call occurring on an SS7 or ISDN network.

### Claim 5 (depends on 3)

The system of claim 3 wherein the release action table enables the system to translate automatically cause conditions for one switching node to a different switching node for corrective action on the network.