Hi,
I use v3.3 with the default db backend for customer login and need to integrate it with an in-house-built customer experience portal (view reports/bills/marketing materials/etc.).
The customer should login only once (in the portal) and then seamlessly jump between the portal and OTRS. The OTRS authentication & session lifetime should be settled transparently behind the scenes between the systems (i.e. log out / switch id from portal => same in OTRS).