Which two features require or may require configuring a SIP trunk? (Choose two.)

A.
SIP gateway

B.
Call Control Discovery between a Cisco Unified Communications Manager and Cisco Unified Communications Manager Express

C.
Cisco Device Mobility

D.
Cisco Unified Mobility

E.
registering a SIP phone

Explanation:
All protocols require that either a signaling interface (trunk) or a gateway be created to accept and originate calls. Device mobility allows Cisco Unified
Communications Manager to determine whether the phone is at its home location or at a roaming location. Cisco Unified Mobility gives users the ability to redirect
incoming IP calls from Cisco Unified Communications Manager to different designated phones, such as cellular phones.
Link: http://www.cisco.com/en/US/docs/voice_ip_comm/cucm/admin/8_6_1/ccmsys/a08sip.html#wpxref77849