Дополнительные сведения о связях между сайтами в ConfigMgr

Understanding Site to Site Communication in SMS/SCCM: http://blogs.msdn.com/b/steverac/archive/2010/07/16/understanding-site-to-site-communication-in-sms-sccm.aspx
Cross-Forest Communications Between Configuration Manager Sites: http://blogs.technet.com/b/pauljones/archive/2009/03/04/cross-forest-communications-between-configuration-manager-sites.aspx