Central Call Control for Mobile and Remote Access Registered Endpoints

Call Flow for Mobile and Remote Access Registered Endpoints

Question

Which call flow matches traffic from a Mobile and Remote Access registered endpoint to central call control?

Answers

Explanations

Click on the arrows to vote for the correct answer

A. B. C. D.

A.

The correct answer is C. Endpoint > Expressway-C > Cisco Unified CM.

Explanation:

Mobile and Remote Access (MRA) is a feature in Cisco Unified Communications Manager ( Cisco UCM) that enables endpoints such as IP phones, softphones, and video systems to securely access and use Cisco Unified CM functionality remotely over any TCP/IP network, such as the Internet.

When a Mobile and Remote Access registered endpoint (such as a Jabber client or a Cisco IP phone) wants to initiate or receive a call, it communicates with the Expressway-C server, which is located in the DMZ (demilitarized zone) and acts as a proxy for the endpoint. The Expressway-C server authenticates the endpoint and establishes a secure connection with it. The endpoint then sends signaling to the Expressway-C server, which translates the signaling into the appropriate format and sends it to Cisco Unified CM, located in the internal network.

Cisco Unified CM receives the signaling from the Expressway-C server and processes the call. If the call is destined for another endpoint that is also registered with Mobile and Remote Access, Cisco Unified CM sends the call signaling back to the Expressway-C server, which forwards it to the destination endpoint.

The call flow for traffic from a Mobile and Remote Access registered endpoint to central call control is as follows:

Endpoint > Expressway-C > Cisco Unified CM

Therefore, option C is the correct answer. Option A is incorrect because it has an extra hop to the Expressway-E server, which is not required for traffic from a Mobile and Remote Access registered endpoint to central call control. Option B is also incorrect because it does not include the Expressway-C server, which is required for Mobile and Remote Access traffic. Option D is incorrect because it has an extra hop from the Expressway-C server to the Expressway-E server, which is not required for traffic from a Mobile and Remote Access registered endpoint to central call control.