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ARRIS SURFboard SB6121 Cable Modem

by Motorola
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ITEM# 13682464
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Technical Specifications

  • Description
  • General Information
  • Technical Information
  • Interfaces/Ports
  • Media & Performance
  • Network & Communication
  • Physical Characteristics
  • Miscellaneous

ARRIS SURFboard SB6121 Cable Modem


Your customers want high-bandwidth data and multimedia services. Our easy-to-use SB6121 SURFboard eXtreme Cable Modem helps you deliver. Harnessing the power of DOCSIS 3.0, the SB6121 enables channel bonding of up to four downstream channels and four upstream channels-so you can offer your customers advanced multimedia services with data rates of more than 100 Mbps in each direction.

Strengthen your broadband leadership. Count on the Motorola SB6121 to help you deliver innovative, ultra-broadband services to your premium customers.

General Information
Manufacturer ARRIS Group, Inc
Manufacturer Part Number 575319-019-00
Manufacturer Website Address
Brand Name ARRIS
Product Line SURFboard
Product Model SB6121
Product Name SURFboard SB6121 Cable Modem
Product Type Cable Modem
Technical Information
Modulation 128QAM
Host Interface RJ-45
F-type Yes
Network (RJ-45) Yes
Number of Network (RJ-45) Ports 1
Media & Performance
Broadband Transmission Speed 222.5 Mbit/s
Network & Communication
Ethernet Technology Fast Ethernet
Network Standard 10/100/1000Base-T
Physical Characteristics
Form Factor Desktop
Height 5.2"
Width 5.2"
Depth 1.7"
Weight (Approximate) 1.35 lb
Additional Information
  • Offers innovative, high-bandwidth data and multimedia services to customers
  • Backward-compatible to DOCSIS/EuroDOCSIS 1.x and 2.0
  • DOCSIS 3.0-certified (EuroDOCSIS 3.0-based)
  • Channel bonding of up to 4 downstream and 4 upstream channels 1 GHz capable tuners
  • Supports IPv4 and IPv6 to expand network addressing capabilities
  • Enhanced security: supports Advanced Encryption Services (AES) traffic encryption
  • Remotely configurable and monitorable using SNMP and TFTP

Operating Systems:

  • Windows 7
  • Windows Vista
  • Windows XP
  • Windows 2000
  • Linux
  • Mac OS 9 or Higher
Environmentally Friendly Yes
Environmental Certification RoHS

Customer Reviews

5 Stars
4 Stars
3 Stars
2 Stars
1 Stars
  • Most Recent

  • Fast
    Verified Purchase

    This is exactly what I needed in my house. The ARRIS SURFboard SB6121 Cable Modem was a wonderful upgrade to our tech needs. It offers a great solution to a slow internet speed. The unit has simple instructions, and is very well labeled.

    Read More
  • MR
    Verified Purchase

    worked good <<<<<<<<<<<<<<<<<<<

    Read More
  • Quit paying the cable companies

    This modem works very well and has enough ports to connect every component I have. Paid for itself in 7 months by eliminating cable charge for the company provided modem.

    Read More
  • Mrs. Ragin

    Easy to install, and use.

    Read More
  • Not for me
    Verified Purchase

    I am only giving this one star because it was the wrong modem for my use. I had to return it because it didn't have an outlet for my phone.

    Read More
  • Most Helpful

  • Does what it is suppose to do....
    Verified Purchase

    I'm using the Motorola SURFboard SB6121 Cable Modem instead of renting a cable modem from Comcast (yes, this is an Comcast approved modem). My speeds from Comcast are the same if not a little better with this modem.

    Read More
  • Great
    Verified Purchase

    Works great. Bought this when TWC decided they were going to charge for a lease. SOOOO glad I just bought one. Saving tons of money this way.

    Read More
  • Motorola SURFboard SB6121 Cable Modem
    Verified Purchase

    So far so good. We have been using it for a week and nothing wrong so far !! I do feel like it works faster than the one we had from the company !!! Thanks Overstock !!

    Read More
  • Stopped paying for rental modem
    Verified Purchase

    At a lower price than retail, this has turned out to be a great buy. I think the data transfer is quicker than the rental unit. A wireless router needs to be purchased separately. This is an approved device for Time Warner Cable.

    Read More
  • Comcast compatible
    Verified Purchase

    What can I say? Easy to install, took just a few minutes on the phone with Comcast to get it activated and saves me rental fees. I'm happy.

    Read More

Questions & Answers

  • Q:

    "Is this compatible with time warner cable?"

    • A:

      This modem should be compatible with any ISP.

  • Q:

    "Why did you choose this product?"

    • A:

      Comcast/Xfinity no longer supports my current modem and since they are greedy whores I had to buy a new one just to keep my service working. Hooray for Comcast!

    • A:

      Comcast Xfinity internet service recommended this product for my service.

    • A:

      I no longer wanted to pay rent for a cable modem and this one works with Time Warner Cable...It will be a big savings in the long run!

    • A:

      because i have time warner cable :)

    • A:

      product recommended by cable company.

    Read more Read less
  • Q:

    "Will this modem accomodate both telephone and computer and be compatible with Time Warner cable?"

    • A:

      Hello Tspunky, yes this will work great. Thank you for shopping with us!

  • Q:

    "Does this modem work with Sudden Link services?"

    • A:

      Hello CaliCowtown, this modem will be compatible with any ISP you just need to make sure you have all of the correct connections. Thank you for shopping with us!

  • Q:

    "dose this work with Mediacom?"

    • A:

      Hello, the Motorola SURFboard SB6121 Cable Modem should work with Mediacom without problem. If you have any additional questions please feel free to let us know. Thank you for shopping with us!

  • Q:

    "does this model work with Cox ?"

    • A:

      Hello tfazz, the Motorola SURFboard SB6121 Cable Modem will work with Cox. Please feel free to contact us again with any further questions. Thank you for shopping with us!

    • A:

      Works with Cox. I just had to call and refresh the signal.

    Read more Read less
  • Q:

    "what comes with this modem? Cord? battery backup?"

    • A:

      Hello thresher593, The Motorola SURFboard SB6121 cable modem does not Contain a battery but it does come with the cord. Please feel free to contact us again with any further questions. Thank you for shopping with us!

  • Q:

    "is this Motorola SB6121 cable modem sold at a new modem or used/refurbished?"

    • A:

      Thank you for your inquiry regarding the Motorola SURFboard SB6121 Cable Modem. This is a new item. I hope this information helps you.

  • Q:

    "do you still need a router for wireless or for use with comcast?"

    • A:

      Yes, you need a router for wireless services.

Shopping Tips & Inspiration

Shipping & Returns

Contact Information
Shipping Information:

Our standard shipping method is ground shipping. We also offer expedited shipping for most items. Your final shipping cost and estimated delivery timeframe will be available at checkout.
Standard shipping details
Expedited shipping details

Standard Return Policy for Electronics:

The items must arrive at our warehouse within 30 days of purchase. You must return items in their original condition to qualify for a full refund. We will issue a partial refund of up to 70 percent if returned items have been opened, used, or returned late. More Details

For your protection, all orders are screened for security purposes. If your order is selected for review, our Loss Prevention Team may contact you by phone or email. There may be a two business day delay to process your order.

** Most Oversize orders are delivered within 1-4 weeks. Some orders may take 6 weeks to be delivered.