a cable of this invention includes a core comprising a plurality of coated optical fibers and a filling composition of matter that is disposed about the fibers . typically , the fibers and the filling material are disposed within a tubular member that is disposed within a sheath system . the sheath system includes longitudinally extending strength members and a plastic jacket . the filling composition that fills interstices in the core is one that includes an oil constituent that is a relatively high molecular weight aliphatic hydrocarbon . a relatively small percent by weight of a stereochemically hindered antioxidant system is used to prevent thermal oxidative degradation of the filling material as well as of materials in contact with the filling material . such stereochemically hindered antioxidants will not migrate out of filling material into other cable and fiber materials , thereby increasing their effectiveness . as a result , a relatively low concentration of antioxidant is needed , as compared with the amount used in the prior art . a styrene ethylene propylene copolymer is also included in order to reduce oil separation of the filling material . a colloidal filler is used to impart gel properties to the material .