cable-modems

Paying your ISP to rent one of their cable modems is today’s equivalent of renting a handset from the phone company. Save some money and improve your internet speeds with one of these instead. We’ve included a few very affordable models as well as more feature-rich options ideal for gaming, streaming HD and 4K video, and downloading large files on multiple devices simultaneously.

8. Netgear CM500V Cable Modems

If your subscription includes Comcast’s voice-over-Internet package, the Netgear CM500V is about the simplest way to get it working, thanks to its two built-in phone jacks. It’s not the fastest around, but it’s sufficient for most streaming and gaming purposes.

  • Multiple enhanced calling features
  • Doesn’t work with other companies
  • A bit costly for a 16×4-channel unit

7. Netgear CM1000 Cable Modems

The Netgear CM1000 is built to take advantage of the DOCSIS 3.1 standard, an upgrade to the more common 3.0 technology that runs up to ten times faster than its predecessor. At the moment, though, it’s only compatible with Comcast and Cox.

  • 32 x 8 channel bonding
  • Easy self-activation
  • Price is on the high end

6. Netgear CM1150V Cable Modems

While the Netgear CM1150V is one of the most expensive on the market, it’s also one of the most powerful. It supports the latest in multi-gigabit connectivity, and is among the few such options with fully integrated voice capabilities.

  • 2 telephone ports
  • Prioritizes call bandwidth
  • Compatible with comcast xfinity only

5. TP-Link TC7650 Cable Modems

Thanks to its 24-by-8 channel bonding, the TP-Link TC7650 supplies just about the most bandwidth you can get using the DOCSIS 3.0 protocol. A dual-core processor ensures consistent and reliable operation, and a two-year warranty provides peace of mind.

  • A wide range of isp compatibility
  • Great for 4k streaming
  • Easy to register online or by phone

4. Motorola MB7621 Cable Modems

The Motorola MB7621 is approved for use with nearly every cable company, and is a great way to eliminate the rental fees that add up over time. It features built-in surge protection and is rated for speeds of up to 650 megabits per second.

  • Suitable for multi-user households
  • Usa-based technical support
  • One of the more affordable choices

3. Arris Surfboard SB8200 Cable Modems

If your ISP is on the cutting edge of high-speed data, the Arris Surfboard SB8200 is worth a look. With full DOCSIS 3.1 support, this one is a good way to future-proof your cable connection in case of an impending upgrade to your local services.

  • Two hardwired ethernet ports
  • Great for 4k video streaming
  • Works with a variety of providers

2. Motorola MB8600 Cable Modems

It’s hard to go wrong with the Motorola MB8600 . Made by a company that developed part of the underlying cable internet protocol, this highly reliable model can coax the most data out of your connection for years to come, because it’s capable of gigabit-speed transmission.

  • Three-way bonded router connectivity
  • One alternate rj45 jack
  • High-quality components

1. Netgear CM600 Cable Modems

The Netgear CM600 boasts 24 downstream and 8 upstream channels in order to maximize all but the fastest Internet plans. Its built-in self-activation capabilities allow you to get up and running with your service provider in almost no time at all.

  • Enables low-latency transmission
  • Support for ipv4 and ipv6
  • Excellent price-to-performance ratio

How Cable Modems Work

Basic explanation of DOCSIS

So you have a broadband connection at home/work and are wondering how it all works. Well I hope to explain to you how it works on a low-tech level so you will have a better understanding of how your connection works. Broadband services from cable companies or Multiple Service Operator’s (MSO’s) are normally provided via cable modems and 90% of the cable modems are using DOCSIS (Data over Cable Service Interface Specification). So let’s now look at what DOCSIS is and what is means. DOCSIS defines interface requirements for cable modems involved in high-speed data distribution over cable television system networks (definition from cablelabs.com). With DOCSIS comes the different versions (1.0, 1.1, 2.0, & soon 3.0) and the limits for each version. We are not too worried with the versions and limits between the versions as consumers since we just want speed and security. But the important thing about DOCSIS is that it’s a standard that protects the consumer and vendors by forcing interoperability and keep the cost of equipment down. If the modems where proprietary then the consumers would have to pay a very high price for the modem or would be force to lease them from the MSO’s. Most MSO’s will allow you to use just about any cable modem that is DOCSIS certified. Now not all MSO’s will do this since they have to support all the modems on the plant with firmware upgrades and other issue with support but most of your well known modems should be supported.

Now for the CMTS & Node

Cable modems communicate with a device called a cable modem termination system (CMTS). The CMTS is a router that talks to all the cable modems and routes there traffic to the internet or the MOS’s backbone. There are a few different vendors in the CMTS market but the most recognized is Cisco Systems. Cable modes are typically grouped into regional nodes. A node is most likely your subdivision but could but a smaller or lager area the MSO uses to support all you services. The node is a fiber to RF converter which allows the MOS to send services to you area via fiber up to the point of you local service area and them the services are sent over coax. The size of the node and number of modem customers in that node can make some difference in the speeds of you modem. With cable modems the node is you local access point and the more users the less bandwidth available for all. Most MSO’s over subscribe nodes but try to make sure there is always 50% available bandwidth at peak hours. What this means is that if you are in a heavily loaded node and everyone is downloading files you service can slow some. With how competitive the ISP business is most MSO’s will try to not over subscribe nodes to much with out adding more nodes or splitting then.

Security on the Network

Other things to watch out for is the security of the node. Make sure other subscribers in your node are not able to see you computer and its traffic. This security issue is normally handled by encryption on the modems traffic to the CMTS. Most ISP’s use BPI+ encryption to protect you traffic but you should always use a hardware firewall/router off of any broadband connection. To test the security of the node you can open your windows network places and look to see if any unknown shares are listed. If there is no encryption in the node and you’re on the same subnet you might be able to see other user’s network shares. This is bad if you have pictures or other sensitive data you do not want others to see. Other things to know are that most MSO’s will block ports to your computer network. This is for both there business goals and your protection. MSO’s typically block NetBIOS, SMTP, port 80, and a lot of other virus ports (business accounts may not have port filters). The port blocking is done mostly to protect the customers from viruses and worms that travel quickly over broadband connections.

Signal Levels and Splitters

Let’s now look at the signal level needed to keep your cable modem online and surfing. Most cable modems have a signal range that they need to communicate to the CMTS. The signal levels can differ from vendor to vendor but as a rule of thumb most modems work well from RX -10dbv to +10dbv and TX 40dbv to 56dbv. A lot of modem vendors provide an informational webpage or diagnostic page you can connect too on the modem to see the messages from the modem and it’s levels. The diagnostic page’s IP is different from modem to modem but if you lookup your vendors modem specifications you will be able to see if you modem has this diagnostic page available. Other things to keep in mind is that your cable modem should be on its own coax line from the cable audit box outside or from the main feed you get from the MSO. It’s not a good idea to have your modem on a coax line with a lot of splitters due to each splitter has at least 3.5dbv or loss. And if you have to use a splitter make sure you read the throughput ratings on the splitter it should be at least 5-1000 MHz pass though.