I will try to lay this out as best I can without pictures on here. I need feedback on CAS to CAS proxy design as the docs are as clear as mud :) Four physical locations which are also each an AD site. Two in North America and Two in the UK One each in NA and the UK are internet-facing CAS arrays. The other site in each is a CAS array but not internet facing. All four will be hardware load balanced. The two that are internet-facing will be na.mail.company.com and emea.mail.company.com They will have certificates and host incoming OWA, EAS and RCP over HTTPS The two non-internet-facing will be spr.mail.company.com and rea.mail.company.com and have certificates. So I set up four arrays. The two internet-facing arrays will forward users on mailboxes in the other two sites to their respective arrays? And then I set up all the CAS in the two non-internet-facing sites as NOT INTERNET FACING and then set up their arrays manually using PS after installation? any other pointers? TIA - ChrisExchange Freak | @ntpro | http://geekswithblogs.net/ntpro

For OWA and EAS, proxy can be used For outlook anywhere, RPCProxy component will be used to forward the traffic across sites. So, if site A is internet-facing, you just set OA FQDN of site B to site A, and make sure OA FQDN of site B can be resolved from site A James Luo TechNet Subscriber Support (http://technet.microsoft.com/en-us/subscriptions/ms788697.aspx) If you have any feedback on our support, please contact tngfb@microsoft.com

Are they under same exchange organization, as if it is the same organization only one CAS must be facing the internet, and the other requests will be proxied via Internal and external URLs... my two cents..