DOCSIS

Data Over Cable Service Interface Specification (DOCSIS /ˈdɒksɪs/) is an international telecommunications standard that permits the addition of high-bandwidth data transfer to an existing cable TV (CATV) system. It is employed by many cable television operators to provide Internet access (see cable Internet) over their existing hybrid fiber-coaxial (HFC) infrastructure. The version numbers are sometimes prefixed with simply "D" instead of "DOCSIS" (e.g. D3 for DOCSIS 3).

DOCSIS was developed by CableLabs and contributing companies, including 3Com, ARRIS, BigBand Networks, Broadcom, Cisco, Conexant, Correlant, Harmonic, Hitron Technologies, Intel, Motorola, Netgear, Technicolor, Terayon, Time Warner Cable, and Texas Instruments.

Cross-version compatibility has been maintained across all versions of DOCSIS, with the devices falling back to the highest supported version in common between both endpoints: cable modem (CM) and cable modem termination system (CMTS). For example, if one has a cable modem that only supports DOCSIS 1.0, and the system is running 2.0, the connection will be established at DOCSIS 1.0 data rates.

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