A water blocked communication cable has an outer jacket defining an interior space, a plurality of conductors, such as a plurality of twisted conductor pairs, disposed within the interior space, and a thixotropic, cold pumpable filling compound disposed within the interior space between the plurality of conductors and the outer jacket. The filling compound consists, for example, of a refined mineral oil base and an organic polymeric gelling agent with a dispersion of micro spheres and has a dielectric constant not greater than 1.8.