From: Ludolf Holzheid lholzheid@bihl-wiedemann.de Date: Thu, 25 Jan 2018 18:23:58 +0100
If it was in this diagram, it would be a 'local process' on the application layer.
So, two softwares, netfilter and stunnel, in a computer system. stunnel in the OSI application layer and netfilter in the protocol, network and link layers. That's a relationship.
Obviously nowhere. (Stunnel is not related to the Linux Netfilter.).
Depends on your personal definition of a relationship.
Thanks for explaining, ... Peter E.