Hello Experts,
I am at the end of ideas. We have problems of integreating the SRM-Webdynpro for selecting an external catalog in the portal. A schema of our infrastructure can you see here.
There are different behaviour for the WebDynpro-Application, where you can select an external catalog. 
When we configure the Portal to call the SRM Backend trough the Webdispatcher, then you can use the Link to the catalog. The webdynpro for catalog selection is called via HTTPS.
But if we configure the Portal to call the SRM Backend through the Reveres Proxy, then you can't the Link to the catalog. By the way, the webdynpro for the catalog selection is called via HTTP. I don't know if this is relevant, but I noticed, that ervery time the catalog Link wasn't functional, the selection was called via HTTP.
So what can be the Problem, that we can't open the catalog, while calling the SRM-Backend through a reverse proxy. What for informations do you also need? Where should I look in the configuration, too? I need new viewpoints on this problem, but a solution may also be fine 
Thanks & Greetings,
Thomas