IEC 60794-6:2020 is a sectional specification covering general features of optical fibre cables applicable to outdoor as well as indoor environments, called "indoor-outdoor cables". Indoor-outdoor cables are deployed in outside plant environments as well as in premises thus fulfilling outdoor as well as indoor requirements. Typical application spaces are, for example, extension of a duct cable into a building or using this design for centralized cabling in the central office, the premises or local area network where the same cable is used for the entire length of the cabling link including both the indoor as well as the outdoor portions. Cables which generally possess the characteristics associated with outdoor cable designs having the thermal and mechanical robustness that makes them suitable for use in the outside plant, while simultaneously being relatively flexible, compact and lightweight and exhibiting the fire performance required in indoor premises are specified in IEC 60794-6-10. Flame retardant outdoor cables as specified in IEC 60794-6-20 are used when most of the cable length is deployed as an outdoor cable with a part of its length deployed indoors. The cable design can be derived from a typical outdoor cable design according to the product specifications described in IEC 60794-3. The specific performance related to bend radii according to the installation situation and fire performance according to the regional legislation mainly requires the appropriate selection of the jacket material in combination with other material and/or design considerations. Because of the use in buildings with tighter space restrictions, higher flexibility of the cable is often required for the installation. Often, smaller diameter cables are preferred. Indoor cables which are weatherised as specified in (IEC 60794-6-30) are used when an indoor cable is used outdoors over a short distance (few meters), for example when the network access point (NAP) is very close to the building. The indoor-outdoor fibre optical cable design can be derived from an indoor design (see IEC 60794-2 and IEC TR 62901 for typical applications) with specific outdoor performance features added. Critical parameters are UV stability, and resistance against exposure to humidity.
