Trifox VORTEX and DesignVision thin clients use a special network protocol
for data transfer. This network protocol handles both types of data conversion
that can be required (and sometimes both at the same time):
The conversion process usually takes place on the client, since it's likely to
have more resources to devote to the effort. The only conversion that takes
place on the server is when SQL statements need to be processed.
- Integer byte flipping between little-endian and big-endian machines.
- Character conversion between ASCII and EBCDIC machines.
Here is a detailed look at how the conversion requirements are negotiated at
[ ASCII to EBCDIC Conversion Table ]
- A connect request is sent from the client. The network connect information
sent is always in ASCII (even between two EBCDIC machines).
- On a successful network connection the server sends the byte-order and
character set information to the client.
- The client sends character set information to the server.
- If the character sets differ the server sends a character conversion map
to the client. This map is either a default (see below) or one pointed to
by the environment variable VORTEX_CCMAP_FILE.
- Normal operations. Client does all conversions except SQL statement.
Updated 26 Sep 2005.