# US 12,192,252 B2 · Voice service restoration after element failure > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,192,252 B2 - Document ID: US12192252B2 - Status: Granted - Kind: B2 - Application number: 18/486,877 - Filed: 2023-10-13 - Published: 2024-04-11 - Granted: 2025-01-07 - Earliest claimed: 2018-11-12 - Assignees: Comcast Cable Communications, LLC - Applicants: Comcast Cable Communications, LLC - Inventors: Matthew J. Christopher; Raghavendra P. Hegde - Web page: https://patentgrep.com/patent/US12192252B2 ## CPC - H04L 65/1069: Session establishment or de-establishment - H04L 65/1016: IP multimedia subsystem [IMS] - H04L 65/1073: Registration or de-registration - H04L 65/1104: Session initiation protocol [SIP] - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract A particular computing device providing service to a user device may become unavailable. If a computing device becomes unavailable, a backup computing device may be requested to provide services to user devices on a temporary basis to allow call completion. Messages to the backup computing device instance may indicate the basis for service issues and prompt further action by the computing device, such as registration with an alternative computing device or re-registration with a computing device that was determined to be unavailable. ## Claims ### Claim 1 A method comprising: receiving, by a computing device, a first call invite for a first user device, wherein the first user device is not registered for call handling services with the computing device; handling the first call invite by sending the first call invite to the first user device, wherein the first call invite indicates service restoration; and receiving, from the first user device, a response to the first call invite. ### Claim 2 (depends on 1) The method of claim 1, further comprising: before handling a call invite for an unregistered user device, verifying that the call invite indicates service restoration. ### Claim 3 (depends on 1) The method of claim 1, wherein the first call invite comprises one or more of: an indication that a primary computing device is unavailable, an indication that the primary computing device is restarting, an indication that the primary computing device is out of service, an indication that the primary computing device has failed, or a reason that the primary computing device is unable to process the first call invite. ### Claim 4 (depends on 1) The method of claim 1, further comprising: establishing, based on the first call invite, communication between the first user device and a source device that originated the first call invite. ### Claim 5 (depends on 1) The method of claim 1, further comprising: receiving, after a call associated with the first call invite, a notification that a primary computing device, with which the first user device is registered, is restarting; and causing, based on the notification that the primary computing device is restarting, the first user device to re-register with the primary computing device. ### Claim 6 (depends on 1) The method of claim 1, further comprising: receiving, after a call associated with the first call invite, a notification that a primary computing device, with which the first user device is registered, is out of service; and causing, based on the notification that the primary computing device is out of service, the first user device to register with another computing device other than the primary computing device. ### Claim 7 (depends on 1) The method of claim 1, further comprising: sending, to the first user device and after a call associated with the first call invite, a network-initiated deregistration message to cause the first user device to perform a DNS look up for a new primary computing device. ### Claim 8 One or more non-transitory computer-readable media storing instructions that, when executed, cause: receiving, by a computing device, a first call invite for a first user device, wherein the first user device is not registered for call handling services with the computing device; handling the first call invite by sending the first call invite to the first user device, wherein the first call invite indicates service restoration; and receiving, from the first user device, a response to the first call invite. ### Claim 9 (depends on 8) The one or more non-transitory computer-readable media of claim 8, wherein the instructions, when executed, further cause: before handling a call invite for an unregistered user device, verifying that the call invite indicates service restoration. ### Claim 10 (depends on 8) The one or more non-transitory computer-readable media of claim 8, wherein the first call invite comprises one or more of: an indication that a primary computing device is unavailable, an indication that the primary computing device is restarting, an indication that the primary computing device is out of service, an indication that the primary computing device has failed, or a reason that the primary computing device is unable to process the first call invite. ### Claim 11 (depends on 8) The one or more non-transitory computer-readable media of claim 8, wherein the instructions, when executed, further cause: establishing, based on the first call invite, communication between the first user device and a source device that originated the first call invite. ### Claim 12 (depends on 8) The one or more non-transitory computer-readable media of claim 8, wherein the instructions, when executed, further cause: receiving, after a call associated with the first call invite, a notification that a primary computing device, with which the first user device is registered, is restarting; and causing, based on the notification that the primary computing device is restarting, the first user device to re-register with the primary computing device. ### Claim 13 (depends on 8) The one or more non-transitory computer-readable media of claim 8, wherein the instructions, when executed, further cause: receiving, after a call associated with the first call invite, a notification that a primary computing device, with which the first user device is registered, is out of service; and causing, based on the notification that the primary computing device is out of service, the first user device to register with another computing device other than the primary computing device. ### Claim 14 (depends on 8) The one or more non-transitory computer-readable media of claim 8, wherein the instructions, when executed, further cause: sending, to the first user device and after a call associated with the first call invite, a network-initiated deregistration message to cause the first user device to perform a DNS look up for a new primary computing device. ### Claim 15 An apparatus comprising: one or more processors; and memory storing instructions that, when executed by the one or more processors, configure the apparatus to: receive a first call invite for a first user device, wherein the first user device is not registered for call handling services with the apparatus; handle the first call invite by sending the first call invite to the first user device, wherein the first call invite indicates service restoration; and receive, from the first user device, a response to the first call invite. ### Claim 16 (depends on 15) The apparatus of claim 15, wherein the instructions, when executed by the one or more processors, further configure the apparatus to: before handling a call invite for an unregistered user device, verify that the call invite indicates service restoration. ### Claim 17 (depends on 15) The apparatus of claim 15, wherein the first call invite comprises one or more of: an indication that a primary computing device is unavailable, an indication that the primary computing device is restarting, an indication that the primary computing device is out of service, an indication that the primary computing device has failed, or a reason that the primary computing device is unable to process the first call invite. ### Claim 18 (depends on 15) The apparatus of claim 15, wherein the instructions, when executed by the one or more processors, further configure the apparatus to: establish, based on the first call invite, communication between the first user device and a source device that originated the first call invite. ### Claim 19 (depends on 15) The apparatus of claim 15, wherein the instructions, when executed by the one or more processors, further configure the apparatus to: receive, after a call associated with the first call invite, a notification that a primary computing device, with which the first user device is registered, is restarting; and cause, based on the notification that the primary computing device is restarting, the first user device to re-register with the primary computing device. ### Claim 20 (depends on 15) The apparatus of claim 15, wherein the instructions, when executed by the one or more processors, further configure the apparatus to: receive, after a call associated with the first call invite, a notification that a primary computing device, with which the first user device is registered, is out of service; and cause, based on the notification that the primary computing device is out of service, the first user device to register with another computing device other than the primary computing device. ### Claim 21 (depends on 15) The apparatus of claim 15, wherein the instructions, when executed by the one or more processors, further configure the apparatus to: send, to the first user device and after a call associated with the first call invite, a network-initiated deregistration message to cause the first user device to perform a DNS look up for a new primary computing device.