Does iSupplier Portal & Sourcing are user based license for Supplier User also ??

Hello Gurus,

Hope you are doing well.

In our client we are using below modules and all of them working for internal and supplier users. My question is suppliers user whoever accessing our server via souring or isupplier portal etc also comes under the clients liability as a user based license to pay to oracle ??

I am actually not clear about the user based preptual licensing aspect and wanted to know how other clients tackling this aspect.

What I presume licensing only eligible for internal user for each module not for supplier user.

Hope any one can clearify this question.