Appendix C. Mapping TablesAssociated with TCP/IP Function
Amapping table is an object that contains a set of hexadecimal characters used to
map data from one character set and code page to another. For example,
unprintable characters can be mapped to blanks, and lowercase alphabetic
characters can be mapped to uppercase characters. The system-recognized
identifier for the object type is *TBL.
This appendix:
vIdentifies which command you use to specify your mapping table
vDiscusses creating, reading, and changing mapping tables
– ASCII and EBCDIC when using TELNET and FTP
– ASCII line drawing character set when using TELNET
– 3270 when using TELNET
vShows the ASCII and EBCDIC mapping tables used by TELNETand FTP
previous to Version 2 Release 1 Modification 1
The default character mapping between ASCII and EBCDIC and between EBCDIC
and ASCII for TCP/IPwas changed at Version 2 Release 1 Modification 1 to make
the mapping for some special characters consistent across the TCP/IP applications
on systems using the English language character set/code page of 101/37.
TCP/IP uses ASCII-to-EBCDIC and EBCDIC-to-ASCII character mapping tables
during TELNET,FTP and SMTP processing. Previous to Version 2 Release 1
Modification 1, the character mapping tables used for FTP and TELNET on English
language systems were QTCPASC and QTCPEBC, which were found in the
QUSRSYS library.The QTCPASC mapping table was used for the
EBCDIC-to-ASCII character mapping. The QTCPEBC mapping table was used for
the ASCII-to-EBCDIC character mapping. Beginning in Version2 Release 1.1, the
default character mapping for FTP and TELNET on English language systems was
changed to be consistent with the SMTP application. The default character mapping
is changed on English language systems only; the default character mapping
remains unchanged on other systems.
Note: Message CPX8416 is used to determine the EBCDIC-to-ASCII character
mapping and the ASCII-to-EBCDIC character mapping on theAS/400
system.

National Language Support Mapping

The subject of national language support (NLS) mapping with coded character set
identifiers (CCSIDs) is discussed in the
International Application Development
.
Many TCP/IP functions now allow the use of CCSIDs.
Using CCSID support is preferable to using mapping tables. IBM recommends that
you use CCSID support when it is available.
© Copyright IBM Corp. 1997, 1999 517