Here’s a blogcast showing how to enable local or remote roaming boundaries in SMS 2003. The blogcast talks about how to enable BITS to ensure bandwidth throttling and the benefits of assigning local or remote roaming boundaries depending on link speed. You can read about BITS in the Advanced client section of the deployment guide
This enables a finer degree of control when software packages are distriuted, and allows clients to download software packages from an alternate site within their boundary.
The blogcast runs for 3 minutes 22 seconds, and is optimised for streaming. You can find links to other blogcasts here.