Data over Cable Surface Interface Specification may be the standard, but it has its disadvantages, as cdlp does. Docsis time-shared bandwidth can clog connections, especially when several users are on the same network, which can slow the data transmission through docsis cable modems. Some critics say that docsis lacks security and quality of service (QoS) as well as nonsymmetrical. Upgrades in docsis 2.0 may allow symmetrical data streams of up to 30 Mbps. The nonsymmetrical and slower data streams can hinder VoIP, but docsis upgrades will allow voice-over to fly through docsis cable modems.
Wireless Docsis
You’ve gone wireless, but is your wireless cable modem a docsis cable modem? There are wireless cable modems designed specifically to be Data Over Cable Surface Interface Specification compatible. Motorola’s wireless cdlp cable modems have been superseded by wireless certified docsis cable modems/gateways. Cisco-Linksys offers the Wireless-G Cable Gateway WCG200E that is docsis certified. Other wireless docsis cable modems include Thomson’s TCM390. For a full list consult http://www.cablelabs.com.
Docsis 2.0 Modems
Want to find out more about what is docsis? If you’re looking for a Docsis 2.0 modem, fear not: Twenty-two cable modems are now Data over Cable Surface Interface Specification certified. Motorola, the inventor of cdlp, has achieved Docsis 2.0 certification for its cable modems/gateways. To find out if your cable modem manufacturer sells a Docsis cable modem certified for version 2.0, visit the CableLabs Web site at http://www.cablemodem.com. Modems from Terayon, Texas Instruments and Thomson recently achieved Docsis 2.0 status.
If your Docsis modem is still version 1.1 or 1.0 and your manufacturer hasn’t achieved 2.0 status, you don’t need to worry, since no matter the version Docsis is the industry standard.
Docsis
What is Docsis? Docsis stands for Data Over Cable Surface Interface Specification, and is the project of CableLabs. It defines interface requirements for cable modems involved in high-speed data distribution over cable television system networks. Docsis is the “Good Housekeeping” seal for cable modems. A Docsis cable modem has been certified by CableLabs and is thought to be acceptable for commercial sale and for use in cable Internet connections. Previously, the cable modem standard was cdlp (cable data link protocol), a proprietary standard made by Motorola. Cable Internet providers and cable modem manufacturers are replacing or have replaced the old cdlp modems with Docsis cable modems. Although many systems will support both cdlp modems and Docsis cable modems, many networks have converted to Docsis and have abandoned the cdlp networks. Docsis is thought to be a less expensive technology standard for consumers.
Docsis 2.0
Docsis 2.0 is the latest standard of Data over Cable Surface Interface Specification. Unlike Motorola’s cdlp, Docsis 2.0, in addition to the features of Docsis 1.0 and 1.1, offers more secure software for Docsis cable modems, which means added security for your Internet connection. Docsis 2.0 also offers the following:
• Significantly enhanced upstream capacity
• 6.4 MHz maximum upstream channel width
• 30.72 Mbps maximum upstream channel capacity
• Increased robustness to upstream noise and channel impairments
This simply means if your Docsis cable modem is Docsis version 2.0, it offers a faster, more reliable connection than previous versions, which in turn are faster and more reliable than cdlp cable modems.
Not Docsis Certified
If you’re a customer of Australian’s Bigpond cable Internet service, Bigpond has most likely replaced your cdlp cable modem with a Docsis cable modem. Bigpond has switched from its cdlp network standard to a Data over Cable Surface Interface Specification network standard.
If you have Motorola’s CyberSURFR cdlp cable modem, Motorola also manufactures a hybrid cdlp/docsis cable router, for those of you who don’t want to surrender your cdlp cable modem. Although Net posters have proclaimed, “CDLP is dead, move on,” some cable modem buyers prefer the cdlp system. That said, most cable Internet providers and cable modem manufacturers favor Docsis.
EDocsis
EDocsis and Docsis Set-top Gateway (DSG) are two new Data Over Surface Interface Specification projects being developed by CableLabs. The DSG integrates docsis technology into a digital set-top cable box, makes it Web-enabled, and increases the two-way capabilities of the average docsis cable modem currently on the market. Its technology is to current docsis cable modems what docsis cable modems are to cdlp cable modems. You can get Scientific-Atlanta’s Explorer 8300 (TM) system, the first digital cable box system to be DSG certified.
EDocsis stands for embedded docsis, which feeds directly into a cable network’s docsis channel, Web-enables cable boxes, and solves end device/traffic management, configuration and security issues to reduce customer cost and improve speed and quality. EDocsis is the basis for DSG, and thus for Scientific-Atlanta’s Explorer 8300 (TM) system. If you want a more integrated cable TV/Internet experience that can give a larger multimedia experience, eDocsis and DSG may be for you.
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