AASTRA 4420 IP Basic (SIP) for MX-ONE User Guide - Manual (Page 46)

Group Features
Dialog 4420 IP Basic 46
Group Features
Group Call-pick-up
People working in a team can have their phones programmed by
their system administrator to form Call-pick-up groups.
In a Call-pick-up group, any member can answer any individual call
to group members. u
Lift the handset. *8#
Press
Press to answer.
Notes:
One Call-pick-up group can serve as an alternative to
another group. Calls to the alternative group can only be
answered when there are no calls to your own group.
Finland and Sweden, press
* 0 #
.