I don't think we should add this registry key in the servers out of US region. Instead, just make sure public folder replication is working fine between regions; and make sure CAS servers between each regions are connecting well. Fiona Liao TechNet Community Support

yeah, i am also suspecting the same, got the below article which pointing to NO instead CAS ( all regions ) has to download or copy from other region (US) OAB generation servers and download it to the IIS OAB from there Autodiscovery will take care .. So i am closing this thread here . Thanks . http://blogs.technet.com/b/exchange/archive/2006/11/15/3397281.aspx

Hello Folks, Small doubt , as per the article Offline Address Book Generation Fails on a Server That Is Running Exchange 2007 Cluster Continuous Replication http://technet.microsoft.com/en-us/library/dd285503(v=exchg.80).aspx in Technet that mentioned events are logged when the EnableOabGenOnThisNode registry entry is missing or when the registry entry contains an invalid server name. So my question is i have exchange server CCR setup in three regions US , ASPAC and EMEA but in that only US server is a OAB generation server can say USNode2 so as per the article we changed the setting in registry and set USNODE2 as this is a active one as of now. So should change the registry setting on other regions servers as well. Other region servers i checked and found that their local servers mentioned in the registry but they are not the OAB generation servers , there is only one in the entire org. and that is US server (US NODE2) and Should i put virtual server name in the other regions servers or it should be the local names only like (ASPACNODE1/2).. Thanks

I don't think we should add this registry key in the servers out of US region. Instead, just make sure public folder replication is working fine between regions; and make sure CAS servers between each regions are connecting well. Fiona Liao TechNet Community Support