High Speed Cable Modem
Cannot Log In to the Cable Modem
If you cannot access the cable modem from computer that is connected to the cable modem
or to a router that is connected the cable modem, check the following:
•If your computer is connected to the cable modem with an Ethernet cable, check the
•Make sure that your computer’s IP address is on the same subnet as the cable modem.
The IP address of your computer must be in the range of 192.168.100.2 to
Internet Explorer, click the Refresh button to make sure that the Java applet is loaded.
•Try quitting the browser and launching it again.
•Make sure that you are using the correct login information. The cable modem user name
admin is lowercase (Caps Lock is off). The default password is password.
If the cable modem does not save changes you made, do the following:
•When entering configuration settings, be sure to click the Apply button before moving to
another page, or your changes are lost.
•Click the Refresh or Reload button in the web browser. The changes occurred, but the
web browser might be caching the old configuration.
Troubleshoot the Cable Internet Connection
If your cable modem cannot access the Internet but the Internet LED lights green , make
sure that the cable MAC address or device MAC address of your cable modem is registered
with your cable Internet provider (see Install and Activate Your Cable Modem on page 7).
The acceptable signal level for the downstream range is from +15 dBmV to –15 dBmV.
Anything more or less than these values results in quality issues. If you use splitters,
removing the splitters can help to clean up the signal.
The acceptable signal level for the upstream range is from 42 dBmV to 49 dBmV. Anything
above the value of 49dBmV results in connection drops and resyncs.
The event log displays time-out messages. For information about viewing the event log, see
View and Clear Event Logs on page 16.
Here are the common time-outs that are seen in the event log:
•T1 Timeout. The cable modem did not receive any periodic Upstream Channel
Descriptor (UCD) messages from the CMTS within the time-out period. This error
message is DOCSIS event message U01.0, Upstream Channel Descriptor. If this error
message is seen multiple times in the event log, contact the L3 ISP support and provide
them the information about the T1 time-outs in the event log.
•T2 Timeout.The cable modem did not receive a broadcast maintenance opportunity in
which to transmit a ranging request (RNG-REQ) within the T2 time-out period