The maximum length (in bytes) needed for the request buffer can be calculated as follows:
maximum Request Buffer Length = (4 + the maximum length of a request string) + (4 + the maximum length of using data, including indicator bytes if User Presence Bits is set to ‘Y’) + (14 if Request Processing Option = P) + (6 for overhead)
The first and fourth lines are always included in the calculation. The second line is included only if data is being sent to the database. The third line is included only if Request Processing Option = P.