Your network has a main office and a branch office. The branch office has five client computers that
run Windows 7. All servers are located in the main office. All servers have BranchCache enabled.
Users at the branch office report that it takes several minutes to open large files located in the main
office.
You need to minimize the amount of time it takes for branch office users to open files located in the
main office.
The solution must also reduce the amount of bandwidth used between the two offices.
What should you do?
A.
At the main office, configure the Quality of Service (QoS) Packet Scheduler on all servers.
B.
At the main office, configure the servers to use Background Intelligent Transfer Service (BITS).
C.
At the branch office, configure the client computers to use BranchCache Hosted Cache mode.
D.
At the branch office, configure the client computers to use BranchCache Distributed Cache mode.
Explanation:
Distributed Cache Mode
Distributed Cache mode uses peer caching to host the branch office cache among clients running
Windows 7 on the branch office network. This means that each Distributed Cache mode client hosts
part of the cache, but no single client hosts all the cache. When a client running Windows 7 retrieves
content over the WAN, it places that content into its own cache. If another BranchCache client
running Windows 7 attempts to access the same content, it is able to access that content directly
from the first client rather than having to retrieve it over the WAN link. When it accesses the file
from its peer, it also copies that file into its own cache. The advantage of distributed cache mode is
that you can deploy it without having to deploy a server running Windows Server 2008 R2 locally in
each branch office. The drawback of Distributed Cache mode is that the contents of the cache
available on the branch office LAN depend on which clients are currently online. If a client needs a
file that is held in the cache of a computer that is shut down, the client needs to retrieve the file
from the host server across the WAN.
Hosted Cache Mode
Hosted Cache mode uses a centralized local cache that hosted on a branch office server running
Windows Server 2008 R2. You can enable the hosted cache server functionality on a server running
Windows Server 2008 R2 that you use for other functions without a significant impact on
performance. This is because if you found that files hosted at another location across the WAN were
being accessed so frequently that there was a performance impact, you would use a solution like
Distributed File System (DFS) to replicate them to the branch office instead of using BranchCache.
The advantage of Hosted Cache mode over Distributed Cache mode is that the cache is centralized
and always available. Parts of the distributed cache become unavailable when the clients hosting
them shut down.
Background Intelligent Transfer Service (BITS)The Background Intelligent Transfer Service (BITS) has two role services: the Compact Server and the
IIS Server Extension. The Compact Server is a stand-alone HTTP or HTTPS file server, whereas the IIS
Server Extension is an Internet Information Services (IIS) plug-in that requires a server running IIS.
IIS Server Extension
The BITS IIS Server Extension lets you configure a server that is running IIS to allow BITS clients to
perform
background, resumable file uploads to IIS virtual directories. On completion of a file upload, the BITS
Server can notify a Web application of the newly uploaded file. This allows the application to process
the uploaded file. The Web application can then optionally reply to the client responsible for the
upload.
Compact Server
The BITS Compact Server is a stand-alone HTTP or HTTPS file server, which allows applications to
host files for BITS clients to download, and allows the asynchronous transfer of a limited number of
large files between computers.
QoS Packet Scheduler
The Quality of Service Packet Scheduler is a Windows platform component that is enabled by default
on Windows Vista® and Windows XP computers. It is, however, not enabled by default on Windows
2003 computers. This scheduler is designed to control the IP traffic for various network services,
including Real Time Communications traffic. This component must be installed and enabled if the
QoS markings described earlier for audio and video traffic are to be implemented by the IP stack.