Connecting to Db2 remotely means the use of a client. Sometimes that client is installed software and other times it is as thin as a JDBC driver. In any event, a client talking to a Db2 server will invoke one or more bound packages on the server side. The source for these packages is supplied by IBM with the client software and must be bound against each target Db2 server. Some of these packages are version-specific and others are not.
All client packages are bound in a collection called NULLID by default.
Read the complete article here: