RFC 3617 (rfc3617) - Page 2 of 7

Uniform Resource Identifier (URI) Scheme and Applicability Statement for the Trivial File Transfer Protocol (TFTP)

RFC 3617                  URI Scheme for TFTP               October 2003


2.  Syntax of a TFTP URI

   A TFTP URI has the following ABNF syntax [2]:

   tftpURI         = "tftp://" host "/" file [ mode ]
   mode            = ";"  "mode=" ( "netascii" / "octet" )
   file            = *( unreserved / escaped )
   host            = RFC 2732 [3]>
   unreserved      = RFC 2396 [4]>
   escaped         = RFC 2396>

   A TFTP URI specifies a file that is to be found or placed on a TFTP
   server.  The "mode" option is an option indicating how the file is to
   be transferred.  If left unspecified, the mode is assumed to be
   "octet".  A third "mail" mode was deprecated at the time RFC 1350 was
   adopted, and is not specified.

2.1.  Encoding Rules

   Aside from syntax as described above, the TFTP protocol does not
   specify length limits to either file names or file sizes.  In the
   case of file names, they may contain any character so long as those
   characters are properly escaped as described above.

3.  Semantics and Operations

   As previously stated the TFTP URI is a reference to a file.  The
   allowed operations on a TFTP URI are read and write.  When a TFTP URI
   is read the underlying mechanisms retrieve the named file via the
   TFTP protocol from the specified host with the optionally specified
   mode.  When a TFTP URI is written the underlying mechanisms transmit
   a file via TFTP to a specified server to either the specified file
   using the optionally specified mode.  No other operations are
   supported.

   Note that it is not possible to retrieve file size information prior
   to retrieval, nor is it possible to determine file existence or
   permissions prior to transfer.  Files transferred may or may not
   arrive intact, as there is no guarantee of reliability or even
   completeness.  See the TFTP standard for more details.  For more
   robust file transfer, consider using either FTP or HTTP [5, 6].










Lear                         Informational