3Com 3100 User Manual page 22

22 C 2: 3C 3100 E T
HAPTER OM NTRY ELEPHONE
Follow these rules for timing the press and release of the hook switch:
If you press and then release the hook switch too quickly, the
system ignores the signal.
If you press and then hold the hook switch for too long, the system
interprets that you have hung up and returns you to dial tone.
Therefore, press and hold the hook switch for approximately one
half second before you release it and move to the next step in the
feature code sequence. Your administrator can set the length of
time that you hold it.