Following on from my post about hyperdrives in science fiction, I thought it was only fair to mention jump gates, which (in Babylon 5 for example) allow entry and exit from hyperspace even when the ship in question doesn’t have its own FTL drive.
A series of jump gates along trade routes means that freighters don’t need to be outfitted with or rely on expensive drive systems. This keeps the cost of running a trade route down. Of course, a jump gate does require power, a lot of it, but since it is close to a trading hub it’s easy to maintain and you get a large number of ships coming and going.
Jump portals (like the Stargate SG-1 supergates) allow for quick intergalactic hops. Convenient, but very costly to maintain because of the enormous power requirements. Still, if it is desirable to open a trade route with a race in another galaxy and deliver goods in a timely fashion, a jump portal might be the solution.
Of course, sensing the opportunity to make a bit of extra profit, whoever maintains such a portal is likely to charge a fee for passage, preferably paid in advance. Who says you can’t have a toll booth in space? 😉