Nortel 2210 User Manual page 21

Features, functions, and buttons 21
End calls
You must end every call, by pressing the Power Off/End Call key, to release system resources and
allow the WLAN Handset to function properly.
If this is not done, it will result in the ringer not ringing for the next call and you might miss an
important call.
Nortel Networks WLAN Handset 2210/2211 User Guide