It appears that the red dotted lines outline the Trusted Third Party (TTP) space. However, it has been brought to my attention that the vertical red dotted line is the Healthcare Organization firewall and that the horizontal red dotted line is the PHA firewall. I suggest labeling and distinguishing these 2 red dotted lines (maybe change the color of one and add text labels?). It may also help to have the S2 split happen simultaneously rather than appearing to go to the TTP first.