Library /sys$common/syshlp/ncphelp.hlb SET, LINE, MAXIMUM RETRANSMITS number  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 Applies only to X.25 lines.  Specifies the maximum number of
 retransmissions of a frame on the specified line. Specify a value in
 the range 1 to 255.  By default, the retransmission value takes the
 network value specified by the NETWORK parameter of the SET MODULE
 X25-PROTOCOL command.  See the Public Network Information manual for
 the network value of this parameter.