All communication between the STEP Application Server and the STEP Client is based on the HTTP / HTTPS protocol. The same goes for the DTP InDesign clients communicating with the PIM application through the respective DTP extensions. The default port is tcp/80, but this can be changed in the sharedconfig.properties file via the System.ServicePort property. If SSL is enabled, the default port is tcp/443, but this default can also be changed via the System.SSLServicePort property.
Administration
The best way to access the Linux server setup is by using an SSH via port tcp/22. Alternatively, VNC or other X server utilities can be used.
HTTP server vs. application server
The system is always set up to run an Apache HTTP proxy as a front end to the application server. The HTTP server receives the incoming requests from the PIM or DTP clients and forwards them to the STEP application server, which then receives the responses and then passes them on to the client applications.
STEP uses Apache 2.2 HTTP Server (on RHEL / OEL 6.x) and Apache 2.4 HTTP Server (on RHEL / OEL 7.x.)
Important: This HTTP proxy is running on the application server itself as part of the STEP application and cannot be separated or removed. If a proxy is required in a DMZ, this must be an additional Apache instance that proxies all requests to the local STEP HTTP proxy.
DTP server
The back-end DTP Server (Adobe InDesign®) listens for requests from the STEP application server on the port specified by the InDesign.Port property (in the sharedconfig.properties file.)
The URL is not configured explicitly, since this is part of the sidecar deployment JAR file generated when adding the InDesign.Instances = <DTP_SERVER_HOSTNAME> property.
The response is delivered back to the STEP application server from the DTP Server, which uses the application server’s URL – taken from the System.Servers property that is also present in the sidecar’s deployment JAR file.