Ports required for communication between Web servers and service applications (the default is HTTP)

We're using SharePoint 2010, I'm the system admin for a SharePoint farm. We enabled SharePoint Search by adding a Search Service APplication. One of the crawl report timer job is failing every 5 minte with the error "Cannot connect to remote server". After digging around, we found that the server running the timer job tries to connect to the SearchAdmin.svc on the index server, over HTTPS / port 32844 However, communication over SSL via a non default port is blocked by our firewall.

According to this article: https://technet.microsoft.com/en-us/library/cc262849.aspx the default is HTTP for communication between web servers. How is it possible that it's trying to connect over SSL?