Imagine the workload that would be
placed on the WDS server if there were 100
clients requesting the same image—packet
1 would be sent 100 times. With multicasting,
when both clients request the same
image, the WDS server sends packet 1 to all
clients that are listening for it, then sends
packet 2, packet 3, and so on. The workimage load on the WDS server is greatly
reduced because each packet is
sent only once. But (and here’s
the bad news), multicast transmission
is similar to broadcast traffic
in that each packet is sent to a
specific multicast IP address, so all
machines will need to look at the
packet to determine whether it’s
addressed to that client.
To create a multicast transmission,
in the WDS snap-in, rightclick
the Multicast Transmissions
node, and choose Create Multicast
Transmissions. On the
Transmissions Name page,
type a friendly name and
click Next. On the Select
Image page, choose your
image group from the Select
the image group that contains
the image drop-down
list provided. Then, choose
your image from the Select
the image list and click Next.
The Multicast Type page,
which Figure 6 shows, lets
you turn on multicast for
a specific image by selecting
Auto-Cast. Auto-Cast
uses new multicast technology
that lets a client join
the multicast transmission
in midstream. For example,
if 20 clients have already
received packet 1624 and a
new client joins, the new
client would receive packet
1624 first and all subsequent
packets until the image has
been sent entirely. Then the
client would ask the WDS
server to start over again
with packet 1.
The Scheduled-Cast
option lets you schedule a
transmission for when multicasting
will be available. Scheduled-Cast
requires that all clients be ready at the same
time because the WDS server won’t restart
from packet 1 after it finishes sending the
image. You have two scheduling options:
Schedule when x number of clients have
requested an image (where x is specified by
you), or schedule the date and time when
multicast will start. After choosing the start criteria for the transmission, click Next. You
have successfully created a multicast transmission
when you see the Task Complete!
message. Click Finish.
One important note about multicast
transmissions: They are available only if the
WinPE you boot the clients with is the boot
.wim file from the Server 2008 DVD/Sources
folder. The version that ships with Vista
doesn’t provide multicast functionality.
Deploying the Image
To deploy an image, perform a network
boot on the client. (F12 will perform a network
boot.) Choose the boot image named
Deploy Image (this is the boot.wim image
you added from either the Vista or Server
2008 DVD/Sources folder). The Windows
Deployment Services Wizard launchs automatically.
Select the language and input
method (e.g., keyboard), and click Next. In
the authentication dialog box, enter your
DomainName\Username. For example, to
authenticate as Administrator in the Bigfirm
domain, type
Bigfirm\Administrator
You can also use a user principal name
(UPN) by typing Administrator@Bigfirm
.com. Provide a password and click OK.
From the list of OS images displayed,
select the image to deploy and click Next.
The Where do you want to install Windows page lets you create and format a partition.
Choose Drive options, New, and type the
size (in MB) of your first partition. Click
Apply. Then select Format, click OK, and
click Next. The Installing Windows screen
opens and displays the phases of the installation
and which one is currently being
processed.
Once the installation is complete, Sysprep’s
mini-setup wizard will prompt you
for information such as administrative
username and password, computer name,
time zone, and a few other things. When
you complete this last wizard, your image
deployment is complete. You can automate
the beginning and ending of your
image deployment process so that you don’t have to choose the size of the first
partition and file system used to format
it or answer Sysprep’s mini setup wizard
questions at the end by creating answer
files. You can find instructions and a list
of settings and values in the “Unattended
Windows Setup Reference” Help file that
ships as part of WAIK.
Just Try It
I hope that armed with this guidance, you’ll
be able to install, configure, and tweak
WDS to fit your environment. Don’t let the
reputation of its predecessor deter you from
taking a serious look at WDS. I think you’ll
be pleasantly surprised. And one thing is for
sure—the price is right!