A communication system including an image processing apparatus configured to, in response to receiving acquisition instruction information from a server via indirect communication, receive authentication information from an information processing terminal device via near-field wireless communication, transmit the received authentication information to the server via the indirect communication, and in response to receiving communication instruction information, which indicates a method for data communication with a service providing apparatus, from the server via the indirect communication, perform data communication with the service providing apparatus in accordance with the received communication instruction information.

An image-forming apparatus includes a controller, a storage, and a communicator. The controller establishes a connection with a terminal device through the communicator by QUIC, stores, in the storage, identification information for identifying the connection and key information to be used for encryption of transmission/reception information transmitted and received to and from the terminal device, performs communication of the transmission/reception information with the terminal device through HTTP/3, and establishes, when the connection with the terminal device is disconnected, a connection with the terminal device using the identification information and the key information so that the communication of the transmission/reception information with the terminal device is resumed.

A communication apparatus includes at least one memory storing instructions, and at least one processor that, upon execution of the instructions, is configured to: wait for connections from other communication apparatuses to a first network built by the communication apparatus, acquire connection information from a first other communication apparatus connected to the first network, search for a second network built by other communication apparatuses, acquire connection information from a second other communication apparatus found in the search, connect to a connection destination indicated by the connection information from the first other communication apparatus and the second other communication apparatus, and wherein the communication apparatus is controlled to switch between waiting for connections and searching for the second network.

A control method for a printing apparatus that receives print data from a printing service using Internet Printing Protocol and executes printing of the print data, includes displaying, a list of print jobs held in the printing service, accepting a print instruction for a print job selected from the displayed list, sending, to the printing service, a request for transmitting print data, and printing based on a received print data in response to the request triggered by the print instruction, using a printing device, and requesting the printing service to transmit print data corresponding to a print job selected from the list, in response to acceptance of a cancel instruction for the selected print job, and discarding the print data received from the printing service, without executing printing based on the print data.

An image reading apparatus is configured to, in a case where access is accepted from a terminal apparatus communicable via a network, establish a session with the terminal apparatus and manage the session. The image reading apparatus is configured to, in accordance with a reading instruction received via the session, perform reading processing for reading an image of an original to generate image data of the read image. The image reading apparatus continues execution of the reading processing as long as access has been accepted via the session at a preset time interval.