SAP PI and Layer7

Dear PI Experts,

We are in a project using PI for integration and a have a security need to pass through Layer7 (an XML firewall).

All communication is done via mediated ABAP Proxies, so Layer7 must be taught to filter the SAP XI 3.0 Protocol.

I did see that Layer7 supports the SOAP with Attachements standard, so that's really encouraging.

The only thing is, it requieres a WSDL to do that.

So this means I have to find the WSDL for the XI Protocol.

Any ideas how do that?

Thanks!!

Roy