microsoft-ds or 445/tcp

From: Doug Fox (dfox138-no-spam_at_hotmail.com)
Date: 10/19/05 

Date: Wed, 19 Oct 2005 14:00:44 -0400

What exactly does "microsoft-ds", 445/tcp, SMB over IP, do?

Is it only for file and print service?
Is it also for file replication?
Is it required for "active directory" replication?
Whatelse do I miss?

I have searched www.microsoft.com and googled the internet. The
microsoft-ds function was not clearly spelled out.

Thanks,

Doug