Cisco 2100 modem

[sternslovchild]

Cable light turns off many times a day. Could be for 1 min, some times 3 hours.  Very intermittent, it's great when it works.

What could be causing this?

[SouthWaleschris]

can u post us ur Modem lower levels upstream and downstream and Model logs (remembering to remove any traces of Mac addresses) so we can see whats happening.... To get these put 192.168.100.1 into ur browser address bar. If asked for a password its root for both.

[sternslovchild]

Channel ID 0  
Downstream Frequency 331000000 Hz
Modulation 256QAM
Bit Rate 10240000 bits/sec
Power Level -10.9 dBmV
Signal to Noise Ratio 36.6 dB
Upstream Channel
The data shown in the table below provides information about the signal being transmitted to the network from your cable modem.

Upstream Status Operational
Channel ID 1
Upstream Frequency 25800000 Hz
Modulation QPSK
Symbol Rate 512000 bits/sec
Power Level 55.0 dBmV

Not sure about the format of this:

Sat Oct 23 13:24:47 2010 Critical (3) Unicast Ranging Received Abort Response - Re- initializing MAC Sat Oct 23 13:02:20 2010 Critical (3) DHCP WARNING - Non-critical field invalid in response. Time Not Established Critical (3) No Ranging Response received - T3 time-out Time Not Established Error (4) ToD request sent- No Response received Time Not Established Critical (3) TFTP failed - configuration file NOT FOUND Time Not Established Critical (3) Received Response to Broadcast Maintenance Request, But no Un... Time Not Established Error (4) ToD request sent- No Response received Time Not Established Critical (3) DHCP WARNING - Non-critical field invalid in response. Time Not Established Critical (3) No Ranging Response received - T3 time-out Time Not Established Critical (3) Unicast Ranging Received Abort Response - Re- initializing MAC Sat Oct 23 12:53:19 2010 Critical (3) No Ranging Response received - T3 time-out Sat Oct 23 12:53:07 2010 Critical (3) Unicast Ranging Received Abort Response - Re- initializing MAC Time Not Established Critical (3) DHCP WARNING - Non-critical field invalid in response. Time Not Established Critical (3) Unicast Ranging Received Abort Response - Re- initializing MAC Time Not Established Critical (3) No Ranging Response received - T3 time-out Time Not Established Critical (3) Unicast Ranging Received Abort Response - Re- initializing MAC Time Not Established Critical (3) DHCP WARNING - Non-critical field invalid in response. Sat Oct 23 11:20:20 2010 Critical (3) No Ranging Response received - T3 time-out Sat Oct 23 11:18:03 2010 Critical (3) Unicast Ranging Received Abort Response - Re- initializing MAC Sat Oct 23 11:17:43 2010 Critical (3) No Ranging Response received - T3 time-out Sat Oct 23 11:13:52 2010 Critical (3) Unicast Ranging Received Abort Response - Re- initializing MAC Sat Oct 23 11:13:29 2010 Critical (3) No Ranging Response received - T3 time-out Sat Oct 23 11:11:23 2010 Critical (3) Unicast Ranging Received Abort Response - Re- initializing MAC Sat Oct 23 11:07:17 2010 Critical (3) DHCP WARNING - Non-critical field invalid in response. Sat Oct 23 11:06:54 2010 Critical (3) Unicast Ranging Received Abort Response - Re- initializing MAC Sat Oct 23 11:04:42 2010 Critical (3) No Ranging Response received - T3 time-out Sat Oct 23 11:03:35 2010 Critical (3) Unicast Ranging Received Abort Response - Re- initializing MAC Sat Oct 23 11:03:06 2010 Critical (3) No Ranging Response received - T3 time-out Sat Oct 23 11:02:23 2010 Critical (3) Unicast Ranging Received Abort Response - Re- initializing MAC Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire QAM/Q... Time Not Established Critical (3) SYNC Timing Synchronization failure - Failed to acquire FEC f... Sat Oct 23 10:58:55 2010 Critical (3) Unicast Ranging Received Abort Response - Re- initializing MAC

[apcyberax]

your downstream power is to low and will need looking at by vm

[Sephiroth]

The low DS power and the high upstream power suggests an attenuation problem to me.  You can read more about this here.

The first thing to check is that your coax cable is firmly connected at each end.  If accessible, you could look to ensure that your outside wall box is watertight and the connector there isn't corroded.

They'll send an engineer out you, I reckon.  He might swap your modem out (I doubt it), but mist likely he'll go to the street cabinet and move you to a tap point with lower attenuation, assuming that one such point is available.  If you are already on the lowest attenuation tap point, and if you're a long way from the street cabinet (are you??) they'll need to think about a cable repull.  But that's getting ahead of things.

The article I pointe4d to should give you an understanding and help you to judge what the engineer is doing.

HTH.

[sternslovchild]

What's a long distance, its about 150m to the box outside.

[Sephiroth]

The article I pointed to gives more information on the effect of cable length - but I reckon your downstream power is attenuated by c. 15 dB compared with someone 50 m away.

There should be an amplifier in the street (a lid with CATV on it sitting flush with the pavement).  This should prevent low downstream power level.  So the amplifier pit could be full of water or the amplifier zonked.

General point is that I reckon you're suffering signal attenuation.

[sternslovchild]

Yep, I can see them things from my window. Always wondered what they were.

Pavement is horrible here, nitty gritty Liverpool 8.

I'll send an email off and sit and wait.

Ta for the help.

[Pete_R]

HI sternslovchild,

I can see that your power levels are fluctuating, and there are a number of power adjustments reflecting on the UBR.

We will need to arrange for an engineer to attend your property to investigate further.

Accordingly, could you please advise of a convenient appointment time from the following timeslots:

Monday-Friday: 8-12, 12-4 and 4-7.
Saturday: 8-12 and 12-4.

[sternslovchild]

Yes any of those times will be ok this week as we can arrange for someone to attend the house.

Please let me know about the next available slot.

Cheers