Sb5120 docsis 3.0 firmware upgrade - Arris SB5100 SURFboard DOCSIS 2.0 Cable Modem (50120900100)

You may need to enable IPV6. All Comcast modem updates are done automatically. I would contact ARRIS for additional assistance. Comcast also has a helpful online community.

Mark
Motorola Mobility Support

Isn't supplied by the ISP? I had one from COX Communications that I had to return when I moved.

The ISP is correct in telling you not owner upgradeable. Only because the upgrade is their property. The firmware is coded for their cable lines to distribute the power levels through the cable. If you're having intermittent disconnects, you should call them and ask for a LEVEL3 tech to come to check the cable connections from the "TAP" (which is where the cable comes to home), it's possibly needed to rewire the cable and splitters in your home

The information may be a bit misleading. What COX said about DOCSIS version is for cable modem standard. The higher the number the better the speed. However, it seems that the modem is already getting THAT speed. Some other device (perhap SS2602) is slowing it down.
It seems that SS2602's WAN side only support 10Mbps connection, which, in term, limit the speed to 10Mbps each way. The actual throughput may be even lower. Should that be the case a new router would be recommanded.

Motorola SB5120
The Motorola SB5120 SURFboard® is a very popular, solid and reliable cable modem compatible with most cable providers. If your modem is two years or older, upgrading to the SB5120 has been known to show speed improvements up to 3X faster than older DOCSIS 1.0 modems. Set up is simple and fast.

• Compact design: With its attractive and compact design, this cable modem won't clutter up your work space
• Easy to maintain: Simplify troubleshooting with the handy font-panel LEDs and built-in HTML-based diagnostics
• Stand-by switch: Disconnect the signal without unplugging the modem with the top-mounted stand-by switch
• DOCSIS™ 2.0: Take advantage of DOCSIS 2.0 technology for up to three times greater upstream capabilities than older modems running on DOCSIS 1.1

Linksys BEFCMU10
Quick to set up at a great price, the Linksys BEFCMU10 offers fast connections to your cable broadband provider. Connect it directly to any PC with an available USB or Ethernet port, and you're ready to surf the Internet. With the Linksys Cable Modem, you'll avoid monthly rent charges, and make the most of your high-speed cable Internet connection.

• Compliant with all industry standards: DOCSIS™ 1.0, 1.1, and 2.0 - compatible with any cable Internet provider
• Ports: Ethernet, USB & Cable
• Buttons: Reset
• LED Indicators: Power, Internet Cable, Internet Activity, Ethernet & USB
• Easy installation: One phone call to your Internet service provider completes the setup

D-Link DCM-202
D-Link's DCM-202 Cable Modem is powered by TurboDOX™ bandwidth acceleration software increasing your download speeds up to 20 times. The DCM-202 makes your broadband connection more efficient and effective by clearing network congestion, resulting in a boost in download speeds. With the DCM-202, you will get more out of your broadband connection with increased bandwidth and enhanced performance.

• Always On, Always Connected
• DOCSIS™ 2.0 Certified
• Ethernet or USB Connectivity

Wireless Routers
Netgear WGT624 Super G 108 Mbps Wireless Router Netgear's WGT624 108 Mbps Wireless Firewall Router is 10 times faster than 802.11b routers providing 4x the range of 802.11b devices, and double the range of most other 802.11g products. Your home network is secure with over 10 security and privacy features including a double firewall and wireless encryption. Netgear's Smart Wizard set up software gets you connected in 5 clicks or less!

• Interoperable with existing 802.11b and 802.11g networks
• Smart Wizard gets you up and running in fewer than five clicks
• Lighted power, test, Internet, wireless and LAN status icons
• Works with most Internet gaming applications that support Universal Plug and Play

Those modems update the firmware automatically. That modem could be as much as 10 years old. As for JTAG upgrade of firmware, you are making this way too hard and expensive. The Jtag is only part of the issue. You have to have an EEPROM flashing machine to connect the cable to and those are not cheap.

It's not the issue with the subnetmask. You said that if you connect directly to the modem, it works. that means the modem is working fine.
Now you have WRT160N router. This router has issues with the firmware. It will be better that you should upgrade the firmware of the router.
Firmware is the software of the router.
Download the latest firmware of the router. Go to the manufacturer's web site and download the firmware of the router.
Open the set up page of the router and upgrade the firmware of the router. Once you upgrade the firmware of the router, reset the router.
On the router you will find a small reset button, hold it down for 30 seconds. release it. wait for 1 minute. Now unplug the power to the router and plug it back in.
Now you will need to reconfigure the router according to the Internet service provider.

May be firmware get corrupted due to power-cut or an excess voltage or surge problem.
At times when there is thunder-storm a lot of excess volatge is generated on the phone wire which is link down to the modem
Ok
try to download recent firmware from manufacturer and see if it can be updated.
Cheers
Uttam

Technical Details

• Model: SB5100
• Type: External, platform-independent modem with HTML-based user interface for status troubleshooting
• Standards: Integrated DOCSIS 2.0 A-TDMA and S-CDMA technology
• PC interface: USB for Windows 98/2000/XP
• Cable interface: F-Connector, female, 75 ohms
• CPE network interface: USB, Ethernet 10/100BaseT (auto sensing)
• LED indicators: Yes (front panel)
• Users: Supports up to 32 users (1 via USB and up to 31 via Ethernet or 32 users on Ethernet)
• Power: Internal power supply: 9 Watts (nominal)
• Input power: 100-240 VAC, 50-60 Hz
• Excite@Home Level 2 Approved: Yes
• Bridging: Ethernet and USB connections are bridged allowing LAN traffic between USB device and Ethernet LAN
• Networking: 10/100BaseT Ethernet (auto sensing)
• Remote management: Yes (via SNMP)
• Software upgradeable: Yes (over the network)
• Top-mounted stand-by button: Yes (enhances network security to end-user)
• Troubleshooting: HTML-based diagnostic user interface
• Global safety approval and certificates: CB scheme (EN60950/IEC950), CE-Evaluation test report (EN55022/EN55024), FCC Part 15, UL 1950
• Downstream demodulation: 64 or 256 QAM
• Downstream maximum data rate: 38 Mbps
• Downstream bandwidth: 6 MHz
• Downstream symbol rate: 64 QAM 5.069 Msym/s
• Downstream symbol rate: 256 QAM 5.361 Msym/s
• Downstream operating level range: -15 to +15 dBmV
• Downstream input impedance: 75 ohms (nominal)
• Downstream frequency range: 88 to 860 MHz
• Upstream modulation: 8, 16, 32, 64, 128 QAM or QPSK (with A-TDMA or S-CDMA enabled CMTS)
• Upstream maximum data rate: Up to 30 Mbps
• Upstream bandwidth: 200 kHz, 400 kHz, 800 kHz, 1.6 MHz, 3.2 MHz, 6.4 MHz (with A-TDMA or S-CDMA enabled CMTS)
• Upstream symbol rates: 160, 320, 640, 1280, 2560 and 5120 ksym/s (with A-TDMA or S-CDMA enabled CMTS)
• Upstream operating level range: A-TDMA: +8 to+54 dBmV (32QAM, 64QAM), +8 to+55 dBmV (8QAM, 16QAM), +8 to+58 dBmV (QPSK), S-CDMA: +8 to+53 dBmV (all modulations)
• Upstream output impedance: 75 ohms (nominal)
• Upstream frequency range: 5 to 42 MHz (edge to edge)
• Data protocol: TCP/IP
• Operating temperature: 0 degrees to 40 degrees C
• Storage temperature: -30 degrees to 80 degrees C
• Operating humidity: 0 to 95 percent R.H. non-condensing
• System requirements: Windows 95/98/2000/NT/Millennium, Macintosh, UNIX
• Width: 2.3 inches
• Height: 6.2 inches
• Depth: 6 inches
• Warranty, parts: 1 year
• Warranty, labor: 1 1year