HiWe are using Exchange 2003 SP2 in a hub and spoke routing group scenario - one HQ, and 6 regional sites. All seven areseperate routing groups.Each regional site has a routing group connector to HQ, but they also have higher routing group connections to each other in case there is an issue with the HQ mail servers. Mail to the Internet flows in/out through HQ, but there is one of the regional sites has a high cost SMTP connector as well.I understand that Exchange 2007 removes the routing group functionality and uses AD sites and services instead.All 7 sites are set up as AD sites and have their own subnet. However, I was wondering how we would recreate these high cost (messaging only) links between the regional sites using Sites and Services?Cheers

Hi, Exchange2007 is a site-aware application. Site-aware applications can determine their own ActiveDirectory site membership and the ActiveDirectory site membership of other servers by querying ActiveDirectory. In Exchange2007, the Microsoft Exchange ActiveDirectory Topology service is responsible for updating the site attribute of the Exchange server object. The routing topology and components of Exchange2007differ significantly from those of ExchangeServer2003 and Exchange2000Server but generally correlate in the following ways: The ActiveDirectory site correlates to routing groupsin Exchange2003 and Exchange2000. IP site links correlate to the concept of routing group connectors. The functionality of the Hub Transport server role in Exchange2007correlates tothe functionality of a dedicated bridgehead server in Exchange2003 and Exchange2000. For ActiveDirectory site, ActiveDirectory clients assume site membership by matching their assigned IP address to a subnet that is defined in ActiveDirectory Sites and Services and associated with an ActiveDirectory site. The client then uses this information to determine which domain controllers and global catalog servers exist in that site and communicates with those directory servers for authentication and authorization purposes. So the ActiveDirectory administrator must define the subnets that are present in the organization and associate those subnets with ActiveDirectory sites. We recommend you to deploy Exchange role in each site with at least on Global Category/Domain Controller. More detail related information share with you: Understanding Active Directory Site-Based Routing http://technet.microsoft.com/en-us/library/aa998825(EXCHG.80).aspx Planning to Use Active Directory Sites for Routing Mail http://technet.microsoft.com/en-us/library/aa996299(EXCHG.80).aspx Hope it helps. Xiu