National Language Support considerations for FTP

This topic provides several points that you need to be aware of when using File Transfer Protocol (FTP) in an environment with different primary languages.

When data is transferred using TYPE E (or EBCDIC), the data is stored as is and therefore will be in the EBCDIC code page of the file that it came from. This can result in the stored file being tagged with an inappropriate CCSID value when the primary language of the two iSeries™ servers is different.
For example, when data in code page 237 is sent using TYPE E to the QSYS.LIB file system on a machine where the file does not exist, the data is stored as is in a new file tagged with CCSID 65535. If the receiving file already exists, then the data will be received as is and tagged with the existing file CCSID which can not be 237.

To avoid incorrect CCSID tagging, you can use the TYPE C CCSID subcommand (for example, TYPE C 237) to specify the CCSID of the data being transferred. When a CCSID is specified on a transfer and the data is written to an existing file, the data is converted to the CCSID of the existing file. If no target file exists before the transfer, a file is created and tagged with the specified CCSID.

In the preceding example, if the target file does not exist, a file with a CCSID of 237 is created on the receiving system. When the target file already exists, the data is converted from CCSID 237 to the CCSID of the target file.
When starting the FTP client, message TCP3C14: Unable to convert data from CCSID &1 to CCSID &2, may be displayed. This occurs if no character conversion is available between the EBCDIC CCSID specified by your job and the ASCII CCSID specified for the this FTP session.
You can change the ASCII CCSID by specifying a value for the coded character set identifier parameter of the STRTCPFTP CL command. CCSID 850, which contains the IBM^® Personal Computer Latin-1 coded character set, is an ASCII CCSID for which character conversions are available to all valid job CCSID values.
When using FTP in ASCII mode between two EBCDIC systems, the data on the system sending the file is converted from its stored EBCDIC code page to ASCII, and then from ASCII to the EBCDIC code page of the receiving system. Typically this does not present a problem because the 7-bit ASCII code page used by the two systems is the same unless the EBCDIC characters on the sending system are not defined in the ASCII code page. Also, some characters in the ASCII code page might be mapped differently between the two different EBCDIC code pages. This might occur if some of the ASCII characters are variant (the character occupies a different hexadecimal code point in an EBCDIC code page). The variant character might be interpreted differently on the receiving system if the EBCDIC code page is different from that of the system sending the file.