Virtual SNR DN Configuration

E.

Virtual SNR DN only supports Cisco Unified SCCP IP phone DNs.

-> Virtual SNR DN provides no mid-call support.

Mid-calls are either of the following: Calls that arrive before the DN is associated with a registered phone and is still present after the DN is associated with the phone.

Calls that arrive for a registered DN that changes state from registered to virtual and back to registered.

-> Mid-calls cannot be pulled back, answered, or terminated from the phone associated with the DN.

-> State of the virtual DN transitions from ringing to hold or remains on hold as a registered DN.

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

A virtual SNR (Single Number Reach) DN (Directory Number) is a feature in Cisco Unified Communications Manager Express (CME) that allows calls to be forwarded to a designated phone number, which may or may not be associated with a physical phone. When a call is made to the virtual SNR DN, the call is forwarded to one or more pre-defined phone numbers, such as a mobile phone or a home office phone. The purpose of this feature is to allow users to be reached at a single phone number, regardless of their location.

Based on the information provided in the question, the correct answer is D. The following is an explanation of each answer choice:

A. Virtual SNR DN supports either SCCP or SIP IP phone DNs.

This statement is incorrect. The virtual SNR DN feature is available on both SCCP and SIP IP phones.

B. A virtual SNR DN is a DN that is associated with multiple registered IP phones.

This statement is incorrect. A virtual SNR DN is a single phone number that is associated with one or more physical phones, but not multiple registered IP phones.

C. Calls in progress can be pulled back from the phone that is associated with the virtual SNR DN.

This statement is incorrect. Once a call has been forwarded to the virtual SNR DN and answered by another phone, it cannot be "pulled back" to the original phone.

D. The SNR feature can only be invoked if the virtual SNR DN is associated with at least one registered IP phone.

This statement is correct. In order to use the SNR feature, the virtual SNR DN must be associated with at least one registered IP phone.

E. A call that arrived before a virtual SNR DN is associated with a registered phone, and still exists after association is made, but cannot be answered from the phone.

This statement is incorrect. If a call arrives before the virtual SNR DN is associated with a registered phone, the call will continue to ring until it is answered or forwarded to voicemail. Once the virtual SNR DN is associated with a registered phone, the call can be answered from that phone.

In summary, a virtual SNR DN is a single phone number that can be associated with one or more physical phones, and is used to forward calls to a designated phone number. In order to use the SNR feature, the virtual SNR DN must be associated with at least one registered IP phone.