Comcast / Motorola sb5100 cable modem dropping connection...

[b4serenity@gmail.com]

Well, I've been offline again for the last few hours again. If those
numbers are good then I THINK I have basically eliminated the signal
/wiring problem... so it's probably my modem?

[Dave]

I had a similar situation a couple years ago. Everything was fine and then
it'd go offline for 15 minutes to a few hours. Of course, when I reported
it they'd schedule a service call and all would be well by the time he
showed up 2 days later. Later another outage and the same problem. I
finally got so frustrated that I went to the local Comcast office, spoke to
the manager and described my frustration. She contacted the local
maintenance manager who called me to discuss it. They finally realized
they had an amp with an intermittent noise problem. They changed the amp
and it hasn't happened since.

If I were you, I'd be escalating the issue and talking to a higher level of
management. In that kind of situation the normal trouble reporting process
is unlikely to work and you'll have to become the squeaky wheel. I'd keep
escalating until you get someone's attention.

That's just my two cents worth.......


<b4serenity@gmail.com> wrote in message
news:1147375711.694391.308740@v46g2000cwv.googlegroups.com...
> Well, I've been offline again for the last few hours again. If those
> numbers are good then I THINK I have basically eliminated the signal
> /wiring problem... so it's probably my modem?
>

[b4serenity@gmail.com]

I just talked with others on my street w/ comcast net service and
they've been fine. So, now that, with the fairly OK signal strength
shown, has me thinking more then ever that it's probably the modem.
I'll give it a shot and see if that does the trick. If it doesn't fix
it then s the ball will be back in comcast's court.

[Ed Nielsen]

I had a situation that started around the end of January that nobody
could figure out. Talked with my assistant state engineer a few times
about it and nothing made any sense. Levels were great and S/N was
great also. Download speeds suddenly dropped to about 1/3 of what they
were previously. Swapped the modem out with one I had previously with
no change. Upload was not affected, just download. Went on for a
couple of months. Eventually, a Chief Tech in Indiana mentioned
something. I bought a new cable modem and voila, back in business.


CIAO!

Ed N.

b4serenity@gmail.com wrote:
> I just talked with others on my street w/ comcast net service and
> they've been fine. So, now that, with the fairly OK signal strength
> shown, has me thinking more then ever that it's probably the modem.
> I'll give it a shot and see if that does the trick. If it doesn't fix
> it then s the ball will be back in comcast's court.
>

[b4serenity@gmail.com]

No new modem yet but here's the latest error log; Does this indicate a
bad signal from Comcast or still possibly a Modem problem? Any help
appreciated!!

Time Priority Code Message
2006-05-12 17:46:54 3-Critical R002.0 No Ranging Response received -
T3 time-out
2006-05-12 17:46:44 3-Critical T001.0 SYNC Timing Synchronization
failure - Failed to acquire QAM/QPSK symbol timing
2006-05-12 17:46:24 3-Critical R002.0 No Ranging Response received -
T3 time-out
2006-05-12 17:46:04 3-Critical R007.0 Unicast Ranging Received Abort
Response - Re- initializing MAC
2006-05-12 17:45:47 3-Critical R002.0 No Ranging Response received -
T3 time-out
2006-05-12 17:45:42 3-Critical T001.0 SYNC Timing Synchronization
failure - Failed to acquire QAM/QPSK symbol timing
2006-05-12 17:45:21 3-Critical R002.0 No Ranging Response received -
T3 time-out
2006-05-12 17:45:07 3-Critical R007.0 Unicast Ranging Received Abort
Response - Re- initializing MAC
2006-05-12 17:44:49 3-Critical R002.0 No Ranging Response received -
T3 time-out
2006-05-12 17:44:43 3-Critical R007.0 Unicast Ranging Received Abort
Response - Re- initializing MAC
2006-05-12 17:41:28 3-Critical R005.0 Started Unicast Maintenance
Ranging - No Response received - T3 time-out
2006-05-12 13:25:23 3-Critical T001.0 SYNC Timing Synchronization
failure - Failed to acquire QAM/QPSK symbol timing
2006-05-12 13:25:19 3-Critical T002.0 SYNC Timing Synchronization
failure - Failed to acquire FEC framing
2006-05-12 13:25:19 3-Critical T001.0 SYNC Timing Synchronization
failure - Failed to acquire QAM/QPSK symbol timing
2006-05-12 13:25:14 3-Critical T002.0 SYNC Timing Synchronization
failure - Failed to acquire FEC framing
2006-05-12 13:25:12 3-Critical T001.0 SYNC Timing Synchronization
failure - Failed to acquire QAM/QPSK symbol timing
2006-05-12 13:25:12 3-Critical T002.0 SYNC Timing Synchronization
failure - Failed to acquire FEC framing
2006-05-12 13:25:11 3-Critical T001.0 SYNC Timing Synchronizatio

[Ed Nielsen]

I don't really know much about log entries, but mine often indicates
"3-Critical R02.0 No Ranging Response received - T3 time-out."

With your numbers being what they are (especially the SNR) and the fact
that no neighbors are experiencing the same issues (especially if 1 of
them is connected to the same tap (cable goes to the same pedestal as
yours), the cable modem seems to be the most likely culprit.


CIAO!

Ed N.

b4serenity@gmail.com wrote:
> No new modem yet but here's the latest error log; Does this indicate a
> bad signal from Comcast or still possibly a Modem problem? Any help
> appreciated!!
>
> Time Priority Code Message
> 2006-05-12 17:46:54 3-Critical R002.0 No Ranging Response received -
> T3 time-out
> 2006-05-12 17:46:44 3-Critical T001.0 SYNC Timing Synchronization
> failure - Failed to acquire QAM/QPSK symbol timing
> 2006-05-12 17:46:24 3-Critical R002.0 No Ranging Response received -
> T3 time-out
> 2006-05-12 17:46:04 3-Critical R007.0 Unicast Ranging Received Abort
> Response - Re- initializing MAC
> 2006-05-12 17:45:47 3-Critical R002.0 No Ranging Response received -
> T3 time-out
> 2006-05-12 17:45:42 3-Critical T001.0 SYNC Timing Synchronization
> failure - Failed to acquire QAM/QPSK symbol timing
> 2006-05-12 17:45:21 3-Critical R002.0 No Ranging Response received -
> T3 time-out
> 2006-05-12 17:45:07 3-Critical R007.0 Unicast Ranging Received Abort
> Response - Re- initializing MAC
> 2006-05-12 17:44:49 3-Critical R002.0 No Ranging Response received -
> T3 time-out
> 2006-05-12 17:44:43 3-Critical R007.0 Unicast Ranging Received Abort
> Response - Re- initializing MAC
> 2006-05-12 17:41:28 3-Critical R005.0 Started Unicast Maintenance
> Ranging - No Response received - T3 time-out
> 2006-05-12 13:25:23 3-Critical T001.0 SYNC Timing Synchronization
> failure - Failed to acquire QAM/QPSK symbol timing
> 2006-05-12 13:25:19 3-Critical T002.0 SYNC Timing Synchronization
> failure - Failed to acquire FEC framing
> 2006-05-12 13:25:19 3-Critical T001.0 SYNC Timing Synchronization
> failure - Failed to acquire QAM/QPSK symbol timing
> 2006-05-12 13:25:14 3-Critical T002.0 SYNC Timing Synchronization
> failure - Failed to acquire FEC framing
> 2006-05-12 13:25:12 3-Critical T001.0 SYNC Timing Synchronization
> failure - Failed to acquire QAM/QPSK symbol timing
> 2006-05-12 13:25:12 3-Critical T002.0 SYNC Timing Synchronization
> failure - Failed to acquire FEC framing
> 2006-05-12 13:25:11 3-Critical T001.0 SYNC Timing Synchronizatio
>

[$Bill]

Ed Nielsen wrote:

> I don't really know much about log entries, but mine often indicates
> "3-Critical R02.0 No Ranging Response received - T3 time-out."
>
> With your numbers being what they are (especially the SNR) and the fact
> that no neighbors are experiencing the same issues (especially if 1 of
> them is connected to the same tap (cable goes to the same pedestal as
> yours), the cable modem seems to be the most likely culprit.

Geez - if you know your neighbors that well, swap modems with one of
them and see what happens.

[Ron W]

Sorry I can't help -- I started having similar problems a couple of
days ago with my Motorola SB 5120 -- occasionally "Send
Channel" light flashes. I suspect I can improve my situation
with a little reduction in cable losses.
My question: How do you access the cable signal levels? Is it
available via a URL?
Thanks.

[Bit Twister]

On Tue, 30 May 2006 13:59:50 GMT, Ron W wrote:
> Sorry I can't help -- I started having similar problems a couple of
> days ago with my Motorola SB 5120 -- occasionally "Send
> Channel" light flashes. I suspect I can improve my situation
> with a little reduction in cable losses.
> My question: How do you access the cable signal levels? Is it
> available via a URL?

http://192.168.100.1

Values from mine:
Motorola Surboard SB5120 QAM 256 (Working range)
Down Power -3 dBmV (-10 and +10 dBmV)
SNR 37 dB (higher than 33dB)
Up Power 47 dBmV (30 and 55dBmV)

[Ron W]

Thanks for your help.
My levels: Downstream = -6 dBmV
Upstream = 54 dBmV.
I still want to reduce losses to get the downstream level up closer to
mid-range.

[$Bill]

Ron W wrote:

> Thanks for your help.
> My levels: Downstream = -6 dBmV
> Upstream = 54 dBmV.
> I still want to reduce losses to get the downstream level up closer to
> mid-range.

I'd be more worried about your *shouting* upstream. Try to remove any
extra splitters and such and make sure you have RG6 cable and tight
connections and if no help there, call them out to look into lowering
your upstream.

[Andrew Rossmann]

In article <kbadnYO_t7fqk-DZRVn-ug@adelphia.com>, news@SPAMOLAtodbe.com
says...
> Ron W wrote:
>
> > Thanks for your help.
> > My levels: Downstream = -6 dBmV
> > Upstream = 54 dBmV.
> > I still want to reduce losses to get the downstream level up closer to
> > mid-range.
>
> I'd be more worried about your *shouting* upstream. Try to remove any
> extra splitters and such and make sure you have RG6 cable and tight
> connections and if no help there, call them out to look into lowering
> your upstream.

In some cases, you may be able to use a tab instead of a splitter. For
a tap, the 'out' port will have little to no loss. The 'tap' port will
have 6db or so of loss (a splitter typically has 3.5db loss on both
output ports). That may be OK for analog TV's or even digital if the
signal is strong enough.

--
If there is a no_junk in my address, please REMOVE it before replying!
All junk mail senders will be prosecuted to the fullest extent of the
law!!
http://home.att.net/~andyross

[lawrence.jones@ugs.com]

Andrew Rossmann <andysnewsreply@no_junk.comcast.net> wrote:
>
> In some cases, you may be able to use a tab instead of a splitter. For
> a tap, the 'out' port will have little to no loss.

There's no such thing as a free lunch. Unless one port has no signal at
all, there's always going to be *some* loss at both ports.

-Larry Jones

Hmm... That might not be politic. -- Calvin

[Roy]

On Tue, 30 May 2006 13:59:50 GMT, no@spam.invalid (Ron W) wrote:

>Sorry I can't help -- I started having similar problems a couple of
>days ago with my Motorola SB 5120 -- occasionally "Send
>Channel" light flashes. I suspect I can improve my situation
>with a little reduction in cable losses.
>My question: How do you access the cable signal levels? Is it
>available via a URL?
>Thanks.


go to 192.168.100.1 from your browser, you should get the modem
configuration manager. You cah look at signal and other things there.

Roy

[bbassett6]

I bought a new computer for my wife and the trouble still existied so I bought a new SB520 surf cable modem. It keeps disconnecting and reconnecting on its own when ever it pleases.

Downstream Value
Frequency 591000000 Hz
Signal to Noise Ratio 31 dB
QAM 256
Network Access Control Object ON
Power Level -15 dBmV

Upstream Value
Channel ID 4
Frequency 34000000 Hz
Ranging Service ID 4009
Symbol Rate 2.560 Msym/s
Power Level 58 dBmV

I guess this falls into the shouting upstream as well. I have the cable coming in toa 4 way split to different rooms. Out of the living room of one leg, is another split going to TV and cable modem. I am going to try to get rid of a split and see if it gets better.

[john_crowley]

I have a Comcast high speed connection, and am using a SurfBoard 5120 cable modem. Over the past few months, I've lost service on average 10 hours per day. Comcast has been out several times, and I've been told everything from the fact that I have too many splitters installed on the line (I recently added a new room added, and as part of it, had several rooms wired for cable tv), to the fact that I need to terminate the unused wall outlets with an "end cap" or "ethernaet terminal plug", to I need a signal enhancer/repeater. The electrciain has come back several time as well, and installed a repeater, but comcast told me that this is useless, i that the device enahnces the signal and the interference. In any event, it doesn't work. My faith in my electrician is less than my faith in the Comcast, but at this point I'm at a loss as to what I should do.

The diagnostics for my cable modem are as follows:

Downstream

Frequency 555000000 Hz
Signal to Noise Ratio 35 dB
QAM QAM256
Network Access Control Object ON
Power Level 1 dBmV

Upstream

Channel ID 4
Frequency 21600000 Hz
Ranging Service ID 6834
Symbol Rate 2.560 Msym/s
Power Level 58 dBmV

Are these values acceptable? Any help/insight would be greatly appreciated!

[BradJohnson2]

I too have started having problems with my Comcast/cable modem in the last two months. It had been working great for the last 8-10 months. The problem has become progressively worse since it started back in May. I get timeouts while surfing the web, which get progressively more frequent until I cycle power. At first, a power cycle would keep me trouble-free a week, now it's about a day.

I finally got around to having Comcast out and, of course, all is good on their end. The tech did "clean up" the taps and drip loop(s) outside, which corrected a my high upstream power reading (was 55-55dBmV, now a solid 46dBmV), but my downstream power remained low at around -9 to -11dBmV. Of course he was an hour early in getting to my house, so I missed him and now I don't know what my readings are inside, except what the SB5100 tells me. I tried disconnecting my cable tv drop, but that didn't help.

Comcast said while the downstream is pretty-much at the limit of acceptable signal level, but it is still acceptable. He suggested my cable modem was to blame and recommended I purchase a new modem and try it.

I did notice that my cable modem was a little warm, so I went to Walmart and bought a 7" clip-on fan for $7. My downstream power is now -7 to -8dBmV and my timeout problems have disappeared. It would also explain why the problem started in May and has become progressively worse (my basement has become warmer with the summer heat). I did take the case apart, but the electronics looked pretty clean, so it's not a dust build-up issue. For now I'm just going to keep the fan on it.

Hope this helps somebody else.

-Brad

[juxtapos99]

I recently got 8 Mbps service from Comcast, but I was having sporadic outages over the past two weeks. A tech came today and he replaced my RCA DCM245 with a Motorola SB5101. The problem is fixed for now.

The tech measured my cable signal with a tester and said my line was fine. Here's my modem info from 192.168.100.1 if this is helpful.

Frequency 615000000 Hz
Signal To Noise Ratio 33.0 dB
Power Level -5.1 dBmV

Channel ID 2
Frequency 30000000 Hz
Power 28.5 dBmV

The cool thing is my speed jumped from around 8 Mbps to 20+ Mbps!! The upload stays at around 765 kbps. So I guess my problem was having a modem that wasn't DOCSIS 2.0 compliant. How fast is everyone else's connection?

http://www.speakeasy.net/speedtest/

(I live in D.C. so I picked the D.C. server to test. All the other servers are much slower for me.)
Last Result:
Download Speed: 19974 kbps (2496.8 KB/sec transfer rate)
Upload Speed: 717 kbps (89.6 KB/sec transfer rate)

Last Result:
Download Speed: 25487 kbps (3185.9 KB/sec transfer rate)
Upload Speed: 718 kbps (89.8 KB/sec transfer rate)

[steve]

lawrence.jones@ugs.com wrote in news:vio3l3-1mk.ln1@jones.homeip.net:

> Andrew Rossmann <andysnewsreply@no_junk.comcast.net> wrote:
>>
>> In some cases, you may be able to use a tab instead of a
splitter.
>> For
>> a tap, the 'out' port will have little to no loss.
>
> There's no such thing as a free lunch. Unless one port has no
signal
> at all, there's always going to be *some* loss at both ports.
>
> -Larry Jones
>
> Hmm... That might not be politic. -- Calvin
>

You are right a tap, or a directional coupler is simply a splitter
that
has a bias on one of the through legs, usually 1 but it increases
with
the frequency, as much as 3 on 860 MHz. Usually a DC has a value of 6
or
9 as a normal 2 way splitter has a value of 3.5. You want to use the
TAP
leg as the minimal drop leg. 53 on the test subjects modem is fine,
they
can go as high as 63.

[seyeklopz]

My connection cuts out every 5 -50 minutes or never, depending on time of day. It only cuts out for 10 seconds or so, but it's hell when I'm trying to play World of Warcraft.

Rogers Extreme Speed Cable Internet (6Mbit/1Mbit), Motorola Surfboard

Frequency 615000000 Hz Locked
Signal to Noise Ratio 39 dB
Power Level -1 dB
Channel ID 3
Frequency 31296000 Hz Ranged
Power Level 39 dBmV
Frequency Plan: North American Standard/HRC/IRC
Upstream Channel ID: 3
Frequency (Hz): 615000000
DHCP Server Enabled
1970-01-01 00:00:30 3-Critical 0x040D9A2C DHCP WARNING - Non-critical field invalid in response.
1970-01-01 00:00:15 3-Critical 0x04E33948 No Ranging Response received - T3 time-out
2006-08-01 05:58:36 3-Critical 0x040D9A2C DHCP WARNING - Non-critical field invalid in response.
2006-08-01 05:58:25 3-Critical 0x04E33A10 Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 timeout
2006-08-01 05:58:10 3-Critical 0x0501BE90 SYNC Timing Synchronization failure - Failed to receive MAC SYNC frame within time-out period
2006-08-01 05:40:21 3-Critical 0x040D9A2C DHCP WARNING - Non-critical field invalid in response.
2006-08-01 05:40:18 3-Critical 0x040D9964 DHCP FAILED - Discover sent, no offer received
2006-08-01 05:40:04 3-Critical 0x04E33A10 Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 timeout
2006-08-01 05:39:46 3-Critical 0x0501BE90 SYNC Timing Synchronization failure - Failed to receive MAC SYNC frame within time-out period
2006-07-31 17:07:53 5-Warning 0x040DC13C DHCP RENEW WARNING - Field invalid in response
1970-01-01 00:00:15 3-Critical 0x040D9A2C DHCP WARNING - Non-critical field invalid in response.
2006-07-25 17:09:06 3-Critical 0x0501BD64 SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing


Is it bad modem, or problem with service?