When an error occurs in an image processor, error information including a performer of the job having been processed upon occurrence of the error, the type of the job, and the type of the error is transmitted to a host. Clients are registered beforehand in the IM server. In response to a third party computing device agreeing to the terms, the wireless service provider indicates to the mobile computing device to allow the third party computing device to access the cellular network via the mobile computing device. A plurality of pressing members are installed at the hub to move back and forth in a radial direction of the hub. In the case where the portion of the requested stream must be retrieved from the content provider, the local service provider attempts to cache the requested blocks in its local cache in addition to streaming the data blocks to the requesting subscriber.