# US 7,505,575 B2 · Method and system for processing telephone calls via a remote tie-line > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,505,575 B2 - Document ID: US7505575B2 - Status: Granted - Kind: B2 - Application number: 11/846,035 - Filed: 2007-08-28 - Published: 2007-12-20 - Granted: 2009-03-17 - Earliest claimed: 2001-01-17 - Assignees: AT&T Labs, Inc. - Inventors: Harold C. Fleischer, III; John E. Simino; Kenneth Robert Stroud - Web page: https://patentgrep.com/patent/US7505575B2 ## CPC - H04M 7/009: {in systems involving PBX or KTS networks} - H04M 7/0096: {Trunk circuits} - H04Q 3/62: for connecting to private branch exchanges - H04Q 3/66: Traffic distributors - H04Q 3/76: Translation from the called subscriber's number to the outgoing or incoming control information - H04M 7/12: for working between exchanges having different types of switching equipment, e.g. power-driven and step by step or decimal and non-decimal - H04M 2207/35: virtual private networks - H04Q 2213/13091: CLI, identification of calling line - H04Q 2213/1313: Metering, billing - H04Q 2213/13141: Hunting for free outlet, circuit or channel - H04Q 2213/13176: Common channel signaling, CCS7 - H04Q 2213/13196: Connection circuit/link/trunk/junction, bridge, router, gateway - H04Q 2213/1322: PBX - H04Q 2213/13222: PBX circuits in public exchange, centrex - H04Q 2213/13224: Off-net subscriber, dial in to/out from network, teleworking - H04Q 2213/1329: Asynchronous transfer mode, ATM - H04Q 2213/13345: Intelligent networks, SCP - H04Q 2213/13383: Hierarchy of switches, main and subexchange, e.g. satellite exchange - H04Q 2213/13384: Inter-PBX traffic, PBX networks, e.g. corporate networks - H04Q 2213/13395: Permanent channel, leased line - H04Q 2213/13399: Virtual channel/circuits - Y10S 379/901: Virtual networks or virtual private networks - H04M: TELEPHONIC COMMUNICATION (circuits for controlling other apparatus via a telephone cable and not involving telephone switching apparatus G08) - H04Q: SELECTING (switches, relays, selectors H01H; wireless communication networks H04W) - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS ## Abstract A method and system include routing telephone calls from multiple private networks via public lines and trunks in a public switched telephone network (PSTN) to a host switch, at which the connections would begin to run parallel. The host switch routes the telephone calls via a private trunk group to a private facility, such as an electronic tandem network (ETN) node or an asynchronous transfer mode (ATM) switch. If the private trunk group is full or unavailable, the host switch routes the telephone calls over alternate private or public trunk groups and selected carriers. ## Claims ### Claim 1 A method for routing a call to a called party number, comprising: determining that the call is subject to a predetermined type of routing, based on an origination identifier; and based on the determination, transmifting instructions to route the call to a designated switch at which call traffic is aggregated and routed over a private trunk group, wherein the designated switch routes calls based on automatic selection of facilities-remote tie-line (ASF-RTL) routing. ### Claim 2 A method for routing a call to a called party number, comprising: determining that the call is subject to a predetermined type of routing, based on an origination identifier; based on the determination, transmitting instructions to route the call to a designated switch at which call traffic is aggregated and routed over a private trunk group; and changing a called party identifier from a first number, corresponding to the called party number, to a second number, corresponding to an identifier of the designated switch. ### Claim 3 (depends on 2) The method for routing the call according to claim 2, further comprising: setting a redirecting number as the first number when the called party identifier is changed from the first number to the second number. ### Claim 4 (depends on 3) The method for routing the call according to claim 3, further comprising: changing the called party identifier back to the first number by referencing the redirecting number. ### Claim 5 (depends on 1) The method for routing the call according to claim 1, wherein the designated switch is associated with a private network associated with the called party number. ### Claim 6 A method for routing a call to a called party number, comprising: determining that the call is subject to a predetermined type of routing, based on an origination identifier; and based on the determination, transmitting instructions to route the call to a designated switch at which call traffic is aggregated and routed over a private trunk group, wherein the designated switch is associated with a private network associated with the called party number, the origination identifier is associated with the private network, and the call is routed over a public switched telephone network (PSTN) prior to determining that the call is subject to the predetermined type of routing. ### Claim 7 A network device that provides instructions for routing a call to a called party number, wherein the network device determines that the call is subject to a predetermined type of routing, based on an origination identifier, and based on the determination, the network device transmits instructions to route the call to a designated switch at which call traffic is aggregated and routed over a private trunk group, wherein the designated switch routes calls based on automatic selection of facilities-remote tie-line (ASF-RTL) routing. ### Claim 8 A network device that provides instructions for routing a call to a called party number, wherein the network device determines that the call is subject to a predetermined type of routing, based on an origination identifier, based on the determination, the network device transmits instructions to route the call to a designated switch at which call traffic is aggregated and routed over a private trunk group, and the network device changes a called party identifier from a first number, corresponding to the called party number, to a second number, corresponding to an identifier of the designated switch. ### Claim 9 (depends on 8) The network device according to claim 8, wherein the network device sets a redirecting number as the first number when the called party identifier is changed from the first number to the second number. ### Claim 10 (depends on 9) The network device according to claim 9, wherein the network device changes the called party identifier back to the first number by referencing the redirecting number. ### Claim 11 (depends on 7) The network device according to claim 7, wherein the designated switch is associated with a private network associated with the called party number. ### Claim 12 A network device that provides instructions for routing a call to a called party number, wherein the network device determines that the call is subject to a predetermined type of routing, based on an origination identifier, and based on the determination, the network device transmits instructions to route the call to a designated switch at which call traffic is aggregated and routed over a private trunk group, wherein the designated switch is associated with a private network associated with the called party number, the origination identifier is associated with the private network, and the call is routed over a public switched telephone network (PSTN) prior to determining that the call is subject to the predetermined type of routing. ### Claim 13 A computer-readable medium comprising an executable program for routing a call to a called party number, the program comprising: routing determination code that determines that the call is subject to a predetermined type of routing, based on an origination identifier; and instruction transmission code that, based on the determination, transmits instructions to route the call to a designated switch at which call traffic is aggregated and routed over a private trunk group, wherein the designated switch routes calls based on automatic selection of facilities-remote tie-line (ASF-RTL) routing. ### Claim 14 A computer-readable medium comprising an executable program for routing a call to a called party number, the program comprising: routing determination code that determines that the call is subject to a predetermined type of routing, based on an origination identifier; instruction transmission code that, based on the determination, transmits instructions to route the call to a designated switch at which call traffic is aggregated and routed over a private trunk group; and code that changes a called party identifier from a first number, corresponding to the called party number, to a second number, corresponding to an identifier of the designated switch. ### Claim 15 (depends on 14) The computer-readable medium according to claim 14, wherein the program further comprises: code that sets a redirecting number as the first number when the called party identifier is changed from the first number to the second number. ### Claim 16 (depends on 15) The computer-readable medium according to claim 15, wherein the program further comprises: code that changes the called party identifier back to the first number by referencing the redirecting number. ### Claim 17 (depends on 13) The computer-readable medium according to claim 13, wherein the designated switch is associated with a private network associated with the called party number.