Secure communication between WAN links

["Epidemic SomeGuy" <epidemic.mail () gmail com>]

Hi, I am working on an assignment planning and implementing a windows
2003 network.
We have a small organisation with departments on different locations.
One of the assignments was to secure the communication between two
sites connected trough WAN links.
The question is:
What is the "best" solution to use to secure the communication between
these two sites?
We can only use Windows 2003 servers.. no 3rd party software, or
hardware based solutions..
The connection speed between the sites is 256 Kbps.
I guess an IPSEC tunnel or something like that is the right way to go,
but i don't have any experience doing this, and I want to be sure I'm
implementing it the right way.
I have googled a while, but I cant find any articles describing my
choices,  and how to correctly install and implement it.
(not enough to make an intelligent decision anyway).

Sorry about my bad English and thanks for your help!

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