Problems with Motorola SURFboard Gateway SBG6580 DOCSIS 3.0 Wireless Cable Modem

Motorola SURFboard SBG6580 Wireless Cable Modem is an all-in-one home networking solution that's quite popular among consumers. At Cautionista, we take a detailed look whether this product has the usual shortcomings of any all-in-one product.










Here's a summary of what we found. These were actual problems seen by customers -

• Constantly disconnects from service provider Time Warner. Connection is lost for a few minutes, every couple of hours.
• GUI is not very intuitive. Even changing the router's password needed a lot of research.
• The firmware that's shipped with the router - SBG6580-3.1.0.0-GA-07-180-NOSH - caused connection drops with Comcast. The stable firmware is SBG6580-3.3.1.0-GA-09-058-NOSH (dated 02/08/2012), however, it's extremely difficult to update the firmware of this router.





• Wireless performance of the SBG6580 appears to be worse than that of a 2Wire Wireless-G DSL gateway, even though the SBG6580 is the newer Wireless-N technology.
• This modem is quite light on features - only 10 port-forwarding, filtering or triggering. No QOS feature.
• Doesn't support simultaneous dual-band - that is - you have to manually select 2.4GHz band or 5GHz band. If your home has mixed 2.4/5GHz capable devices, you need to run the router at 2.4GHz, which loses the advantage of dual-band.
• Wireless connection is extremely flaky and seems to have a firmware update that would fix it. Motorola website says contact Comcast to update the firmware. Comcast says they don't have any new firmware. So, it doesn't seem wise to buy an all-in-one modem/router if the firmware cannot be updated to fix the router side of the all-in-one.
• Worked OK for a few hours, but then the modem kept losing internet connection. Motorola tech suspected incoming signal strength issue, but the signal appeared to be strong based on the dB readings from the modem. However, after replacing with separate Motorola SB6120 modem and Netgear N600 router, the connection was stable.
• The router side of the SBG6580 encountered delays and timeouts for DNS lookups which made web access very slow. ISP's signal strength was fine. The delays could be due to a bug in the firmware or might be due to a slow processor inside the all-in-one, which probably is unable to keep up with both the functions - cable modem as well as router.
• Wireless is unstable at 5GHz, barely enough signal strength at 2.4GHz, hence not much advantage in having the Wireless-N dual band feature.
• Modem has to be rebooted at least once in 24 hours to restore internet connection. Two pieces of SBG6580 were tried, both had the same problem. No problems after replacing with separate  Motorola SB6120 modem and Linksys E1200 router.
• Wireless signal is weak even 15 ft away from the router.
• The modem started dropping connections after around 6 months of use.
• The modem died while trying to connect to wireless. Couldn't come back up again. Comcast tech that came out said they have seen several issues with the SBG6580.
• Firmware upgrade not available to customers who already purchased the modem.
• The SBG6580 could not connect to Cox ISP. The tech advised to purchase separate modem and router, instead of this all-in-one.

Solutions

• Many of the issues with the SBG6580 modem are possibly due to overheating.
  
  
  
  Here are some solutions that worked for some customers to avoid the overheating issue.
  • Locate the SBG6580 in a well-ventilated area. Keep it away from other electronic devices that may generate heat. For example, do not place it on top or near a PC that gets warm. Do not keep it in an area that gets hit by direct sunlight or near a fireplace. Place it on top of a table, and not inside a shelf.
  • Blow a clip-on fan onto the modem to cool it down. Lower speed setting of the fan should be fine. You would hear some noise even in this setting though...
• Disable the router function on this all-in-one and just use it as a cable modem. Connect your own separate router to it. This pretty much solves most of the connection and wireless problems, since the router part of the MotorolaSBG6580 seems to be causing most of it. Here's how to do it:

1. Disconnect the coaxial cable from the modem.
2. Press down the white reset button on the back panel of the modem with a pen or pencil for around 30 seconds. This resets all settings to factory defaults.
3. Turn the modem off and back on. Once it's up again, plug in a computer or laptop with an ethernet cable into the modem. It's important to connect using ethernet cable and not through wireless.
4. Connect to http://192.168.0.1 from a browser on the computer, and login with username: admin and password: motorola
5. Make a few changes:

Wireless -> Primary Network -> Disabled

Basic -> Setup -> NAPT Mode -> Disabled

Advanced -> Options -> Rg Passthrough -> Enable

Advanced -> Options -> Passthrough Mac Addresses -> Enter the WAN MAC address of the separate router that you plan on connecting to the Motorola modem. This is an optional step and is needed only if the router doesn't work when you first connect it.

Basic -> DHCP -> No


6. Now disconnect the ethernet cable from your computer/laptop and connect it to the WAN (Internet) port of your router. Leave the other end of the ethernet cable connected to the Motorola modem.
7. Connect the coaxial cable back into the modem and power cycle it.

Alternatives to the Motorola SURFboard Gateway SBG6580:

Most people who returned their SBG6580 purchased separate modems and routers and their internet connections were stable afterwards. Here are some of the customers' choices that worked out fine for them -

• Motorola SB6120 SURFboard DOCSIS 3.0 eXtreme Broadband Cable Modem and Netgear N600 Wireless Dual Band Router WNDR3400
• Linksys DOCSIS 3.0 Cable Modem (DPC3008-CC) and  Airport Extreme 802.11N (5TH GEN) router
• Linksys DOCSIS 3.0 Cable Modem (DPC3008-CC) and  Linksys E1200 router
• Motorola SB6120 SURFboard DOCSIS 3.0 eXtreme Broadband Cable Modem and D-Link DIR-601 router. 

Issues with Linksys DOCSIS 3.0 Cable Modem model DPC3008-CC

Linksys by Cisco is one of the best brand names in the home networking industry. Cautionista takes a good look to see if the Linksys DOCSIS 3.0 Cable Modem (model DPC3008-CC) lives upto the brand name.









Some of the issues that customers found with this Cable Modem are -

• Modem hangs up and then reboots several times a day. Unable to even load the modem status page at 192.168.100.1 when this happens.
• Connection drops every 30 minutes. Linksys and Comcast support just keep referring to one another.

Firmware issue

The intermittent connection issues mentioned above were seen by multiple Comcast customers of the DPC3008 modem. The solution seems to be quite simple - Linksys is unable to help the customers because Comcast is responsible for maintaining the firmware of any modem that connects to their network. Customers need to ask Comcast to revert the firmware on the modem back to August 2011 version. This was seen to fix most of the customer issues. Hence, Cautionista doesn't see any issue with the purchase of Linksys DOCSIS 3.0 Cable Modem (DPC3008-CC) for a stable and reliable internet connection.

Problems with Motorola SURFboard SB5101U DOCSIS 2.0 Cable Modem

Although DOCSIS 3.0 modems are becoming popular nowadays, the 38 Mbps download / 30 Mbps upload speeds supported by DOCSIS 2.0 modems are probably more than enough for most customers of Cable broadband providers like Comcast, Roadrunner, Cox, Charter, etc. Among the DOCSIS 2.0 modems, the Motorola SURFboard SB5101U Cable Modem is one of the popular models among consumers. Just because it's popular doesn't mean that the modem would be trouble-free. As always, Cautionista takes a detailed look at issues with this modem and presents to you so that you could decide to buy with confidence or stay a mile away from this modem.

Here are some of the issues that we found, as reported by customers of this Motorola modem -

• The SB5101U modem died after around 2 weeks of operation. Some stopped working after a month or so. Could be a few defective pieces.
• When using the modem connected to computer via USB port, it had to be reset many times a month to restore internet.





• Motorola doesn't have a warranty when the modem is purchased by individual consumer, the warranty is applicable only if modem is supplied by the Cable Internet Provider. Pretty much the warranty is meaningless for the individual consumer.
• Upstream of modem died after around 1 year.
• Unable to connect to the internet out of the box. Again, probably a bad piece.
• Unable to register the modem with Comcast, although the modem was seen by the ISP.
• Ethernet port became loose after 2 months, hence unable to connect to the internet.
• Comcast tech was unable to register the modem because it said that the device serial number was already in use. It's possible that someone mistakenly entered this modem's serial number or the modem might have been used or returned by someone else.

As you can see, the modem is a relatively trouble-free device. There are a few occasional bad pieces like any other electronic device. At Cautionista, we don't think there's any major risk in purchasing the Motorola SURFboard SB5101U Cable Modem. Some customers say that they have had a more stable internet connection using  Linksys by Cisco DPC3008. You pay a few dollars more, but gain the Cisco quality and peace of mind that comes with it.

Motorola SB6121 SURFboard Cable Modem Problems

Motorola SB6121 SURFboard DOCSIS 3.0 Cable Modem is generally considered a good choice for replacing the modem that you lease from your Internet Service Provider (Comcast, Charter, TimeWarner Roadrunner, Cox, ...). Here at Cautionista.com, we always do our due diligence by looking for any serious issues with the modem. We also offer some solutions and alternatives for this modem.








Here's a summary of the problems that we found with the SB6121 cable modem in our detailed research. These problems were seen by actual customers of the modem -

• Motorola Surfboard SB6121 keeps resetting / rebooting every couple of minutes, hence unable to register the modem with Comcast. 
• The SB6121 doesn't tolerate signal issues (noise, weak signal) as much as the older ones like SB6120. 
• Takes a long time (more than 10 minutes) to establish a link with Comcast, after powering up the modem. 
• Download speed is too low - around 100kbps even for a 15Mbps service from Comcast.
• Random disconnections occur every few days.
• Unable to self-install the modem with Comcast, even a Comcast technician was unable to install it.
• Worked for couple of months, then just died.
• Modem unable to receive signal from Comcast, confirmed by technician.





• Download speed gradually reduces over time, until you reboot the modem.
• The SB6121 cable modem overheats.
• Need to keep a ping running in order to maintain connection.
• Although runs at higher upload/download speeds, the connection wasn't stable.
• Connects to Comcast fine, but disconnects when a router is connected to this Cable modem.
• Dead on Arrival (DOA). The modem kept power cycling by itself for no reason.
• The modem remains in a constant loop of self-test, with all LEDs cycling.
• Modem connects to Comcast, but loses it's IP address every few minutes.
• Modem doesn't seem to be fully compatible with Comcast, although it's listed as an approved DOCSIS 3.0 device.
• No password option available, hence not secure.
• SB6121 may not yet be supported for Comcast Business Class service.
• Motorola doesn't seem too willing to honor their warranty, blaming the problems on the Service Providers like Comcast.

Based on the long list of problems seen by other customers of this modem, Cautionista.com thinks that it's quite risky to buy a Motorola SB6121 SURFboard Cable Modem, as it doesn't seem to be of a good build-quality, as they call it in the industry. You too may face one of the problems mentioned above, and may have to return the modem.

Solutions / Workarounds that worked for some SB6121 customers

Many of the issues with the SB6121 modem are due to overheating of the device. Here are some solutions that worked for some customers to avoid the overheating issue.

• Keep the SB6121 in a well-ventilated area. Keep it away from other electronic devices that may generate heat. For example, do not place it on top or near a PC or router that gets warm. Do not keep it in an area that gets hit by direct sunlight. Place it on top of a table, but not inside a shelf.
• Blow a clip-on fan onto the modem to cool it down. Lower speed setting of the fan should be fine. Even this setting would generate some noise though...

Alternatives for Motorola SB6121 SURFboard Cable Modem

Here's what other customers purchased, after returning their SB6121 modems. The customers didn't seem to face any issues with these modems, and their connections were stable.

• Motorola SB6120, the previous model. Surprisingly, the previous model seems to be of a better quality than the SB6121.
• Linksys by Cisco DPC3008. You pay a few dollars more, but gain the Cisco quality and peace of mind that comes with it.
• Arris WBM760A. This model has been Comcast OEM for a while.
• Motorola SB5101U. This is DOCSIS 2.0 technology, upto 38 Mbps max download speed, and is considered extremely reliable.
• uBee DDM3513.