Unable to Establish at 192.168.100.1

[WaltNVA]

I recently had Cox digital telephone installed.  The modem was upgraded from a Motorola SB5120 to a SBV5220.  I am no longer able to establish a connection at http://192.168.100.1 to check my cable modem signal levels. I either get a banner message "Internet Explorer cannot display the webpage" or I am challenged for a Username and a password to Login on an otherwise blank green screen.  I read elsewhere to enter "root" for both the username and password challenge, but that does not work.  I have never had that happen before with http://192.168.100.1.  Is it because I switched modems?  How do I now go about checking my cable modem signal levels?
THANKS!

[ale52]

Can you ping 192.168.100.1 / get an instruction manual with the new modem / is it a modem router or just a modem / reset the modem to defaults?

Alan <>< 

[contrex]

user        admin
password motorola

[WaltNVA]

Thanks!  The Username and Password obtained access.  My readings are:

Downstream SNR: 37
Downstream Power: +12dBmV
Upstream Power: 41dbvM

On a side note, I have a Viewsonics (Model VSMA 608-C-10R) amplifier that receives the incoming RG6 coaxial cable at the garage point-of-entry and splits it 8 ways without signal loss (as opposed to a 1:8 splitter).  The viewsonics amp has a 3.5dB gain on each pathway and a 0.0dB return path loss. I retrofitted my entire house with 8 homeruns of Belden 1694A RG6 coaxial cable to work in conjunction with the Viewsonics amp; one of the homeruns goes directly to my cable modem.
 
Is it necessary to perhaps introduce a 1:2 splitter at the cable modem (and terminate the unused outbound) to reduce the downstream power, or is +12dBmV acceptable given the SNR reading?

THANKS again!

[contrex]

Looks Ok to me. I would leave it alone unless i was getting trouble. Perhaps your particular service supplier would have an opinion about that +12dBmV. It's within the DOCSIS spec though.

Here are your readings, cut with my UK ISP's recommendations for acceptable performance

Downstream SNR: 37

Downstream SNR: should be 30 dB or higher: the higher the better.

Downstream Power: +12dBmV

Downstream Received Power: the DOCSIS specification requires cable modems to function correctly with downstream power levels in the range -15 dBmV to +15 dBmV

Upstream Power: 41dbvM

The upstream transmit power will lie within the range +8 to +58 dBmV, with many ISPs specifying a target commissioning level below +55 dBmV. Values in the forties are the most common.