Siemens HiPath 4000 - Manual (Page 23)

Make a call – Comfort Functions
23
Step by Step
Holding a call on a line key (not for UK)
Precondition: Your telephone has a "Hold" key.
Press the key. The line key lamp flashes slowly.
Continuing a call on a line key
Press the key. The lamp lights up.
Hold
Your HiPath 4000 system can also be configured
in such a way that the call is held when the line
key is pressed. Try this for yourself or enquire
with System Support.
Line