The issue that I am experiencing is very similar to this issue: https://communities.ca.com/thread/241751026, however in my case, I am not sure if I have all of the correct ports open in the firewall, and/or if there is a problem with how the ticket system is configured.
For this ticket system, we are using version 12.6.
Externally, we have port 443 open. The ticket system itself is accessible externally (https://[external URL]/CAisd/pdmweb.exe), but anything related to Tomcat does not work, such as pictures and attachments. As a result, it also appears that the web service URL (http://[external URL]/axis/services/USD_R11_WebService) is not working either. Tomcat and the web service URL work internally.
When I had asked my network administrator about configuring the ticket system to be available externally, he had said that he is only able to open 1 port for the application.
We also have the ticket system configured to use IIS and Tomcat. The internal users use IIS for authentication. Our plan is to use Tomcat and the web service to authenticate external users via a web service application.