The maximum amount of data that Mainframe Access should send or receive through the TCP/IP network software in one send or
receive operation. Specify 0 (zero) to allow Mainframe Access to use the optimum buffer size; this is recommended, as it will
reduce the number of send or receive calls made to the TCP/IP network software. Specify an explicit value in the range 512
to 32767 only if you have diagnosed a problem with your TCP/IP network software that is associated with large message sizes.