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Contoso, Ltd., is a manufacturing company that has 4,000 employees. The company has a sales department, a marketing department, a research department, and a human resources department.
The company has four offices. The offices are configured as shown in the following table:
The New York office contains the main data center. Communications for all of the offices is routed through the New York office.
All telephone calls from the Los Angeles office and the Miami office are routed through a public switched telephone network (PSTN) gateway in the New York office.
All offices connect to each other by using a wide area network (WAN) link. Each office connects directly to the Internet.
Active Directory Environment
The company has an Active Directory Domain Services (AD DS) forest named contoso.com. The forest contains a single domain. All domain controllers run Windows Server 2008 R2.
Each office contains two domain controllers. Each office is configured as an AD DS site.
Each office contains DHCP servers that run on 32-bit servers.
Skype for Business Server Environment
The company has nine servers. The servers are configured as shown in the following table:
The company uses a SIP domain of contoso.com. The voice infrastructure is configured as shown in the following table:
All users are enabled for Enterprise Voice. The company also contains the Edge environment configured as shown in the following table:
The Miami office has a dial plan. The dial plan is configured as shown in the following table:
The Skype for Business server configuration has five routes. Location-based routing is not configured. The routes are configured as shown in the following table:
The PSTN usage for the users in the Los Angeles Office is configured as shown in the following table:
The company identifies the following issues with the current infrastructure:
Los Angeles users report that the audio quality during calls to the New York office is poor and that the calls often disconnect.
Users in the Miami office report that when their WAN link fails, they cannot establish calls to the PSTN.
The Miami users report that they cannot call the Los Angeles users by using a five-digit internal phone number.
The company plans to implement the following changes:
Provide voice resiliency in all of the offices if a WAN link fails.
Implement Call Park.
Implement an unassigned number range that has a voice announcement.
Add an additional auto attendant.
Implement a gateway in the Los Angeles Office that uses the local PSTN.
Migrate several users to Skype for Business Online. The users will use instant messaging (IM) with Skype for Business users only. Client computers will use automatic configuration and open federation. The migrated users will use a SIP domain of cloud.contoso.com.
Provide a backup route for each office if a gateway fails.
Provide each office with access to the local PSTN.
The company identifies the following technical requirements:
Enable five-digit internal dialing that uses the site code and the last four digits of the phone number range.
Configure the New York gateway as the backup route for the local gateway in each office.
Changes to the infrastructure must minimize the number of new servers deployed.
You collect the following call statistics for users in Los Angeles:
Peak call concurrency is 25 percent.
Fifty percent of all placed calls are routed to the public switched telephone network (PSTN).
Thirty percent of all placed calls are internal calls to users in the other offices.
Twenty percent of all placed calls are conference calls.
The average bandwidth for peer-to-peer calls is 65 kilobits per second (Kbps).
The average bandwidth used for conference calls is 100 Kbps.
You need to allocate the minimum amount of bandwidth required on the wide area network (WAN) link for the planned implementation of the voice gateway in the Los Angeles office. All calls to the PSTN will be routed through the local voice gateway in the Los Angeles office.
How much bandwidth in megabits per second (Mbps) should you allocate?
A. 7.20 Mbps
B. 3.95 Mbps
C. 10.00 Mbps
D. 2.25 Mbps