Communication protocol for non-internet-enabled devices

A non-transient computer readable medium containing program instructions that, when executed, cause a computer to synchronize an electronically controlled set of lockers and at least one server providing access to the electronically controlled set of lockers, wherein the electronically controlled set of lockers does not have an internet connection and cannot communicate with the at least one server, the program instructions comprising program instructions for:

• receiving, at the set of lockers and from a client, a request for the client to operate the set of lockers, wherein receiving the request comprises receiving from the client an authorization granted to the client by the at least one server;
• and
• in response to determining, based on the authorization, that the client is authorized to operate the set of lockers:
• operating the set of lockers based on one or more messages received from the client,
• keeping, at the set of lockers, a message in a device buffer for transmission to the at least one server via the client until an acknowledgement of successful receipt of the message is received from the server, the message indicating that the set of lockers have been operated based on the one or more messages received from the client, and
• transmitting to the client, for communication to the at least one server, an event log, the event log comprising an indication that the set of lockers were operated based on the one or more messages received from the client, wherein the event log includes events that occurred at the set of lockers prior to receiving the request for the client to operate the set of lockers.