1.9.13  Using Your phone in Parallel with a Wired Telephone
(One-numbered extension)
Two telephones connected to the 
KX-NS1000 can be set to share 1 extension number, and both telephones
can be set to ring (One-numbered Extension feature). You can choose whether the sub extension associated
with the main extension will ring when an incoming call is received.
To set
PT/SLT/SIP Extn.
Off-hook.
Press lit DSS of the paired telephone. 
Or enter     41 and then dial extension 
number of the paired telephone.
Talk.
OR
14
extension no.
(DSS)
C.Tone