In which call state does the Mobility soft key act as a toggle key to enable or disable Single Number
Reach for Cisco Unified Communications Manager Express SCCP IP phones?

A.
idle

B.
seized

C.
alerting

D.
ringing

E.
connected

Explanation:
Pressing the Mobility soft key during the idle call state enables the SNR feature. This key is a toggle;
pressing it a second time disables SNR.

http://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucme/admin/configuration/guide/cmead
m/cmesnr.html