Data Over Cable Service Interface Specification (DOCSIS) (often pronounced “dock-sis”) is an international standard developed by CableLabs and contributing companies that include ARRIS, BigBand Networks, Broadcom, Cisco, Conexant, Correlant, Harmonic, Intel, Motorola, Netgear, Terayon, and Texas Instruments. DOCSIS defines the communications and operation support interface requirements for a data over cable system. It permits the addition of high-speed 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 first DOCSIS specification was version 1.0, issued in March 1997, with revision 1.1 (adding Quality of Service (QoS) capabilities) following in April 1999. Because of increased demand for symmetric services such as IP telephony, DOCSIS was revised to enhance upstream transmission speeds; DOCSIS 2.0 was released in December 2001. Most recently, the specification was revised to significantly increase transmissions speeds (this time both upstream and downstream) and introduce support for Internet Protocol version 6 (IPv6). This version, DOCSIS 3.0, was released in August 2006. 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 and cable modem termination system (CMTS).
As frequency allocation band plans differ between U.S. and European CATV systems, DOCSIS standards have been modified for use in Europe. These changes were published under the name of “EuroDOCSIS”. The wider bandwidth in EuroDOCSIS architectures permits more bandwidth to be allocated to the downstream data path (toward the user). EuroDOCSIS certification testing is executed by Excentis (formerly known as tComLabs), while DOCSIS certification testing is executed by CableLabs. Typically, Customer Premises Equipment receives “Certification”, while CMTS equipment receives “Qualification”.
Japan employs other variants of DOCSIS.
What does it do ?
docsis is a small program that can be used to generate binary configuration files for DOCSIS-compliant cable modems. DOCSIS stands for Data over Cable Service Interface Specification and is a standard developed by Cablelabs.
You can download the specifications from Cablelabs’ website. The relevant specification is the Radio Frequency Interface Specification, which contains the bulk of the standard.
This program is useful for people/operators using DOCSIS Cable Modems that want to implement their own provisioning system, or for people testing/working with DOCSIS technology in general. Otherwise, there’s nothing you can do with it. It is not destined to end-users.
How advanced it is ?
docsis supports most DOCSIS 1.0 configuration settings. The format of the configuration file was designed to be human-readable. Here are some examples.
New configuration settings are easy to add based on the infrastructure that is already in place. Let us know if you need new configuration settings, or better add them yourself and send us a patch .
Currently only the main DOCSIS 1.1 configuration settings are supported (Packet Classifiers, Service Flows etc). If you need more you can go ahead and implement them yourself !
source: wikipedia.org sourceforge.net