The only "parallel" I can see is that it revolves around the crew of a merchant ship that is trying to eke out a living in space - this is hardly a concept that is unique to Traveller though (and isn't really a central point of Traveller either since you could just as well be running a Scout campaign or a Mercenary/Military campaign). The idea that the characters may have had a past history of doing different careers is also not unique to Traveller.
Otherwise, the setting and the tech and the politics are totally different. The varying tech levels between the Frontier and Core worlds could easily be a parallel to the more 'civilised39; towns that were around in the civil war era vs the ones out in the frontier (and while the TLs of worlds in Traveller varies, they don't do so with any consistency - it's fairly likely that you'd find high tech frontier worlds and low tech core worlds).
Otherwise, the setting and the tech and the politics are totally different. The varying tech levels between the Frontier and Core worlds could easily be a parallel to the more 'civilised39; towns that were around in the civil war era vs the ones out in the frontier (and while the TLs of worlds in Traveller varies, they don't do so with any consistency - it's fairly likely that you'd find high tech frontier worlds and low tech core worlds).