What is binary file transfer?
Binary file transfer (BFT) describes the syntax and semantics required to represent files that are transferred using fax modems. Binary file transfer is a standard used to transfer data files over protocols from various telematics services, including fax group 3 and 4, teletex, and data transfer and manipulation (DTAM) normal mode.
Binary files contain binary-encoded data types used for computer processing and storage. Binary files consist of sequences of bytes in which the binary digits are grouped in eighths. They can contain text, pictures, and compressed versions of other files or sounds. Some binaries have headers in them. When they do not contain headers, they are called flat binaries.
In order to transfer binary files through systems that do not allow certain data values, they must be translated into plain text format. Such a translation increases the file size by 30 percent. Files are translated back to binary files upon receipt at the destination.
Binary data messages sent consist of sequences of certain attributes, which include the file data itself. The sequence of the name component is the graphic string file name. If more than one element is encoded, the first element is the filename and the remaining elements are prefixes for filenames. Another attribute, called the Allowed Action Attribute, defines the set of actions that will be taken on the file. This includes reading, inserting, replacing, expanding, deleting, etc.
The content type attribute contains the abstract data type of the file content and the structuring information necessary to maintain the complete file structure and semantics during the transfer of the binary file. The storage account attribute identifies the authority responsible for the accumulated file storage charges. The value of the storage account attribute is of type graphic string. Date and time attributes indicate the time at which the file was created. The value of this attribute type is a generalized time. The date and time of the last modification attribute indicate when the file content was last modified.
The recipient attribute indicates the final user destination of the binary file transfer. The character set attribute indicates the international character set to be used to render the character data contained in the attribute data file contents. The compression attribute specifies an optional compression that is added to the contents of the data file contents. The access control syntax defines conditions under which access to the file is valid.