A first apparatus for providing an internet of things, IoT interworking service, comprising a processor (91, 81), a memory (82, 93), and communication circuitry, the first apparatus being connected to a network via its communication circuitry, the first apparatus further comprising computer-executable instructions stored in the memory of the first apparatus which, when executed by the processor of the first apparatus, cause the first apparatus to perform operations comprising: a. sending, to a second apparatus, a discovery request, the discovery request being sent in a first service layer protocol, the second apparatus being an IoT device; b. receiving, from the second apparatus, a response to the discovery request, the response including information regarding the second apparatus which is to be shared with an IoT server and being sent in the first service layer protocol; c. adding, to a repository of device information, the information regarding the second apparatus, the information regarding the second apparatus being derived from the response to the discovery request; d. selecting, based on a repository of server information, the repository of device information and a policy, a third apparatus, wherein the third apparatus is compatible with the second apparatus and is an IoT server; e. sending, to the third apparatus selected according to the policy, a request message, the request message being sent in a second service layer protocol and requesting registration at the third apparatus of the second apparatus; and f. receiving, from the third apparatus, a response to the request message, the response to the request message being sent in the second service layer protocol and indicating whether or not the second apparatus has been registered at the third apparatus, the IoT interworking service provided by the first apparatus by registration of the second apparatus with the third apparatus. a. sending, to a second apparatus, a discovery request, the discovery request being sent in a first service layer protocol, the second apparatus being an IoT device; b. receiving, from the second apparatus, a response to the discovery request, the response including information regarding the second apparatus which is to be shared with an IoT server and being sent in the first service layer protocol; c. adding, to a repository of device information, the information regarding the second apparatus, the information regarding the second apparatus being derived from the response to the discovery request; d. selecting, based on a repository of server information, the repository of device information and a policy, a third apparatus, wherein the third apparatus is compatible with the second apparatus and is an IoT server; e. sending, to the third apparatus selected according to the policy, a request message, the request message being sent in a second service layer protocol and requesting registration at the third apparatus of the second apparatus; and f. receiving, from the third apparatus, a response to the request message, the response to the request message being sent in the second service layer protocol and indicating whether or not the second apparatus has been registered at the third apparatus, the IoT interworking service provided by the first apparatus by registration of the second apparatus with the third apparatus.