Keysight Technologies FieldFox N9912A104 User Manual page 51

CAT (Cable and Antenna Test) Mode
2-Port Insertion Loss Measurements
When measuring very long lengths of cable, it may be necessary to increase
the sweep time. Learn how on page 3-8. Learn why in the Supplemental
Online Help:
http://na.support.keysight.com/fieldfox/help/SupHelp/FieldFox.htm
Keysight N9912-90001 User's Guide 3- 15