Calling WCF service from another WCF service (routing)

i have WCF service (RootService) hosted on IIS on server. For example on port 5000. I need to call another service (AdvancedService), hosted on the same IIS on different port. For example on port 6000. There shouldn't be any problem with calling that.

I would like to ask for routing.

I will call RootService from any client. The request will do through internet. E.G. https://217.48.48.48:5000/RootService.svc. And then my RootService call AdvancedService by https://217.48.48.48:6000/AdvancedService.svc. Will be request routed through the internet, or just only through local network, server or just only IIS?

Thanks for your answer