Here is our issue:

We have external clients who are using ProClarity Desktop Professional. When they access the PAS server, they are required to login. Then when they try to open a briefing book, they are prompted to login again. Two logins is obviously not ideal. The only way we are able to achieve extranet access at all is by using msmdpump.dll to connect to the SSRS cube(s).

We have recently been doing some testing - instead of using the msmdpump.dll, we have published some briefing books on the PAS server which points directly to the SSRS Server (netbios name). We implemented Forefront TMG and thought we would be able to remove the double login by using Forefront and Kerberos (we tried regular and constrained delegation). Internally, users can login to the PAS server and are automatically authenticated to the SSRS cube (we don't even need Kerberos configured to make this work). Externally, this does not work. We are stumped on how to proceed.

Can ProClarity Desktop Professional actually access SSRS cubes externally without logging in twice? If so, how? Any help would be greatly appreciated.