Patent ID: 11956284
Assignee: BLACKBERRY LIMITED
Field: Digital communication (Electrical engineering)
Classification: CPC H  G | IPC G  H

Claim 7:
8. A non-transitory computer readable medium containing instructions that when executed by a processor enable the processor to perform operations comprising:
receiving a SIP request, at a network node from a user equipment (UE) of a user, wherein the network node is in a Session Initiation Protocol (SIP) based network;
responsive to receiving the SIP request, attempting to retrieve a user's profile from a home subscriber server; and
responsive to detecting a failure to retrieve the user's profile from the home subscriber server, sending a first SIP response to the UE of the user, the first SIP response being a SIP server timeout message, the SIP server timeout message including an indication indicating support for restoration procedures, the SIP server timeout message further including at least a first field set to a value equal to a value provided in a Service-Route header field, the Service-Route header field included in a second SIP response to a SIP REGISTER request of the UE, the SIP REGISTER request sent by the UE of the user,
wherein the value sent in the SIP server timeout message includes a Uniform Resource Identifier (URI) representative of the network node in the SIP-based network, the value being usable by the UE to compare with the value provided in the Service-Route header field.