In 11.5 Web Viewer, AdmTool, File – Preferences – Timeouts tab, "Logoff user after ____ minutes of inactivity" and Remote response timeout ___ seconds" and the DRAS Longwait Timeout are the settings we need to coordinate.
For 11.5 Web Viewer, it’s up to the business needs for the values, but the DRAS Longwait Timeout value should be longer than the Web Viewer Inactivity setting. As for the remote timeout value, as long as you do not have a CCI timeout value for CCITCP/CCISSL communications (which is typically very long or off by default), it should be set to accommodate your longest DRAS remote responses. That covers if you do AFP transforms, use EAS recalling from real tape, or make requests of some kind in multi-million line/page reports. The large single page scenario is truncated by 11.5 Web Viewer, so that is generally not relevant in that case.
It’s pretty much the same for 12.1 Web Viewer, just so long as you are at a level above Build 140, so as to handle very large, single page reports.