The message buoy from Pegasis station might be due to the Kilrathi jamming communications during the attack (or perhaps they hit the main comm hardware already, and the buoy was a backup system).
Anyway, in the games at least, the time to cross a system seems to range from several hours to a couple of days, so if we assume that jump points are not clustered in close to the star (i.e. either randomly distributed or else mostly on the edges of the system), then we are talking about speeds on the order of a few percent of the speed of light (i.e. low tens of thousands of km/s). While this is a good one hundred or so times faster than the cruising speeds shown in the games (hundreds of km/s), said cruising speeds are explicitly "with ramscoops open", running a fuel surplus. For quick transit between planets or jump points within a system, it seems that spacecraft will close their scoops and accelerate to much higher speeds.