Communication system, management server, communication relay apparatus, and program

摘要

A technique enables appropriate establishment of tunnel communication between a gateway in a power saving mode and a cloud server, as well as a reduction in power consumption. If a management server (50) that has received from the cloud server (70) a request to access a device (10b) has no communication session with a gateway (30b) corresponding to the device (10b), the management server (50) transmits a tunnel connection request to a substitute gateway (30a) via a communication session with the substitute gateway (30a) (step S34). The substitute gateway (30a) transfers the tunnel connection request to the gateway (30b) and causes the gateway (30b) to return from the power saving mode (S39). Then, the gateway (30b) establishes tunnel communication with the cloud server (70) on the basis of the tunnel connection request (S56).