You are an Enterprise administrator for contoso.com. The company has a head office and two branch offices. All the servers on the network run Windows Server 2008 and all client computers run Windows Vista.
A server on the corporate network of the company run Windows Server Update Services (WSUS) and distributes updates to all computers on the internal network. The WSUS server is configured to store updates locally.
The branch offices connect to the head office by using a dedicated WAN link. You need to design a patch management strategy for the corporate network that would ensure that the branch offices would get updates from the head office. However, the WSUS updates are approved independently for each branch office without increasing the Internet traffic too much.
Which of the following options would you choose to accomplish the desired task?

A.
For each branch office, create organizational units (OUs). Create and link the Group Policy objects (GPOs) to the OUs.

B.
In each branch office, install a WSUS server.

C.
Configure each branch office WSUS server as a replica of the main office WSUS server.

D.
Configure each branch office WSUS server as an autonomous server.

E.
Configure different schedules to download updates from the main office WSUS server to the client computers in each branch office.

F.
Configure each branch office WSUS server to use the main office WSUS server as an upstream server.

Explanation:

To design a patch management strategy for the corporate network that would ensure that the branch offices would get updates from the head office, you need to install a WSUS server in each branch office and configure each branch office WSUS server to use the head office WSUS server as an upstream server.
A WSUS hierarchy supports two modes, autonomous mode (which we will discuss later) and replica mode. In replica mode, the upstream server is the only WSUS server that downloads its updates from Microsoft Update. It is also the only server that an administrator has to manually configure computer groups and update approvals on. All information downloaded and configured on to an upstream server is replicated directly to all of the devices configured as downstream servers. Using this method you will save a great deal of bandwidth as only one computer is constantly updating from the Internet. More importantly however, you will save a countless amount of time since you are only managing one server now from a software standpoint.
Using autonomous mode, the upstream server transmits update files to the downstream servers, but nothing else. This means that individual computer groups and update approvals must be configured for each particular downstream server. In this deployment type, you get the benefit of optimized bandwidth usage with the flexibility of allowing individual site administrators to manage computer groups and update approvals themselves.
http://www.windowsnetworking.com/articles_tutorials/Deploying-Microsoft-Windows-Server-Update-Services.html