Abstract: A quad cable construction and a method of manufacturing the same are provided for use in communications for a local area network, while offering significant vapor migration and petroleum immersion resistance characteristics. A cable is provided with inner and outer jackets encompassing a helix configuration of insulated signal conductors. A core filler is provided to substantially fill the core and interstices between the insulated signal conductors. The core filler and inner jacket are formed of vapor proof material and bound with the insulated signal conductors in a manner that substantially fills all grooves and crevices around the insulated signal conductors to substantially prevent vapor migration along the cable length. An outer jacket may be provided that is impervious to gas, thereby permitting the cable to be submerged in petroleum for extended periods of time without affecting operation.