News Glossary of Terms FAQs Polls Cool Links SpeedGuide Teams SG Premium Services SG Gear Store
Registry Tweaks Broadband Tools Downloads/Patches Broadband Hardware SG Ports Database Security Default Passwords User Stories
Broadband Routers Wireless Firewalls / VPNs Software Hardware User Reviews
Broadband Security Editorials General User Articles Quick Reference
Broadband Forums General Discussions
Advertising Awards Link to us Server Statistics Helping SG About
The Broadband Guide
search advanced
 forgot password?
FAQs Categories:

DOCSIS 2 vs. DOCSIS 3 differences ?

The main difference between DOCSIS 2 and DOCSIS 3 standard cable modems is that DOCSIS 3 allows for a much higher maximum throughput. DOCSIS 3.0 achieves that by using multi-channel bonding (using multiple channels simultaneously for download/upload) while DOCSIS 2 modems do not. A Docsis 3 modem with 4 bonded channels, for example would provide 4 times the bandwidth of a Docsis 2 modem.

Some other technical differences:
Docsis 3.0 supports QAM128 for upstream traffic, while many DOCSIS 2 support only QAM64
Docsis 3.0 specs use 108Mhz to 1.002Ghz downstream, 5Mhz to 85Mhz upstream.
Docsis 2.0 specs use 88Mhz to 860Mhz downstream, 5Mhz to 42Mhz upstream.

Changing to a DOCSIS 3 capable modem isn't going to change your maximum speed up, down or
sideways, only subscribing to an upgraded tier will. However, DOCSIS 3 has the ability to use multiple downstream and upstream channels at the same time (channel bonding) to maintain the maximum possible speed. Because of this, DOCSIS 3 may experience less of a speed drop during peak usage hours vs. a DOCSIS 2 modem. The D3 modem, depending on how new it is and how many channels the ISP makes available, has access to 2x-8x more bandwidth than a D2 modem, allowing for a somewhat more consistent connection.

  Post your review/comments
comment top