dslreports logo
 
    All Forums Hot Topics Gallery
spc
Search similar:


uniqs
525
Iggy_AZ
join:2005-11-21
Surprise, AZ

Iggy_AZ

Member

SB6120 keeps switching to single channel

My Motorola SB6120 after many years of perfect service is now switching from 4 channel bonded to single channel.
This happens at least once a day for the past week.
I reboot and all is fine for a day.
I live in Surprise and have not changed anything on my computer or service.
Anyone see this happen to them?

Hard Harry7
join:2010-10-19
Narragansett, RI

Hard Harry7

Member

What are your signal levels via 192.168.100.1? Also, how old is "may years? Generation 1?
Iggy_AZ
join:2005-11-21
Surprise, AZ

Iggy_AZ

Member

Click for full size
It is about 2 years old.
Here is my modem signal information which all look great and normal.
m8trix
join:2003-12-24
Chandler, AZ

m8trix

Member

that modem older then 2 years, it cam out 5 years ago and stop being produced like 3 years ago. but aside from that your signals are crap, bypass any splitters if you can other wise you need a tech out
Iggy_AZ
join:2005-11-21
Surprise, AZ

Iggy_AZ

Member

M8tris
No splitters. It is a direct line from outside.
What specifically do you see wrong with my signal?
Fubar
join:2015-01-27
Phoenix, AZ

Fubar

Member

said by Iggy_AZ:

M8tris
No splitters. It is a direct line from outside.
What specifically do you see wrong with my signal?

Low Downstream Power Level and Low SNR.

For a direct line that is horrible!

SNR should be above 37 and Power level more around 0

Hard Harry7
join:2010-10-19
Narragansett, RI

Hard Harry7

Member

I would say the SNR is what is breaking the channel bonding. If thats direct from the street then you need a technician.

kv2009
join:2009-09-14
Kenner, LA

kv2009 to Iggy_AZ

Member

to Iggy_AZ
Your upstream power levels look okay but the downstream is terrible, so they'll probably want to run a new line to the house. How long is the line from the pedestal or box to your modem??
Iggy_AZ
join:2005-11-21
Surprise, AZ

1 edit

Iggy_AZ

Member

The line from outside is dedicated and is only about 30 ft long.
I called cox and they said keep monitoring it. LOL
They also tried to sell me another modem and the insurance.
Funny they agreed that something is wrong but mentioned that they have some maint. some where within 10 miles so she didn't want to send anyone out to check my line.
She said keep monitoring it and call her back.
It was a wasted call and will call them again in a week or so.

Here is the information from my modem log.
I removed my MAC address.

Feb 25 2015 09:39:06
5-Warning T202.0 Lost MDD Timeout;CM-MAC=XXXXXX;CMTS-MAC=XXXXXXX;CM-QOS=1.1;CM-VER=3.0;

Feb 25 2015 09:39:06
5-Warning N/A DS Partial Service Fallback: MDD Lost-> CM in DOCSIS 2.0 Recovery Mode ;CM-MAC=XXXXXX; CMTS-MAC=XXXXXXXX;CM-QOS=1.1;CM-VER=3.0;

Hard Harry7
join:2010-10-19
Narragansett, RI

Hard Harry7

Member

I would call back and just straight up ask for a technician. I find it helps to state that up front. I have found the outage reporting to be inaccurate and prone to human error. Have them look at the signal on your street. Does everyone have low DS SNR? If not, then I doubt its a area wide problem. if they don't know how to look at your street, ask to be transferred to someone who does. The worst it will do is raise one more red flag with their dispatch.

PS. Something else to do at the start of the call is ask if there is a outage in your state and where, before you give them your account info.

Mike Wolf
join:2009-05-24
Tuckerton, NJ

Mike Wolf

Member

I get the feeling that if it's an area wide problem more people would be calling in with the same problem and Cox would hopefully relent and send someone out.
chuckkk
join:2001-11-10
Warner Robins, GA

chuckkk to Iggy_AZ

Member

to Iggy_AZ
-10db is likely the problem, since it's at the low limit.
The s/n is a no wonder! heck all that connections on the cable side of the modem to the incoming line.
There is also a remote possibility that the CMTS has a problem that's intermittent.
Iggy_AZ
join:2005-11-21
Surprise, AZ

Iggy_AZ

Member

Modem just rebooted twice in he past hour. When it comes back it is 4 channel bonded.
Each time the logs says
Cable modem reboot due to T4 timeout
No Ranging Response.
Phoenix looks like it has many COX issues now so we will continue to monitor.
No change to my signal values.

CoxTech1
join:2002-04-25
Chesapeake, VA

CoxTech1

Member

The modem is probably rebooting to get the bonded channels back. It'll do this automatically once their available again and there's no significant user activity detected. With levels like yours I'd say it's time for a technician to come take a look.
Iggy_AZ
join:2005-11-21
Surprise, AZ

Iggy_AZ

Member

Thank you CoxTech1.
I appreciate your input which has and is helpful on this forum.
Iggy_AZ

Iggy_AZ

Member

Well Cox Tech came out and said my signal was low and changed the splitter and it seemed to lower a bit from -10 dbmv to about -8 dbmv.
He said it is still within COX specs being -10 to +10 so we will see if I still get switching from 4 channel to single channel.

Hard Harry7
join:2010-10-19
Narragansett, RI

Hard Harry7

Member

said by Iggy_AZ:

from -10 dbmv to about -8 dbmv.

Did he mention why the signal from the street was so low? I get like 11dB direct off my tap, and I can't see 30 feet lowering the signal that much. Sounds like the underlying issue may still need to be addressed. What are your signal to noise levels?
Iggy_AZ
join:2005-11-21
Surprise, AZ

Iggy_AZ

Member

Click for full size
My SNR is 35 dbs.
He said that as long as I stay above -10 dbs I'll be OK.
He said that Cox specs are between -10 and +10 db is OK.
Zero being perfect. If it continues to drop again they may have to look further out towards their switch or amp a few blocks away.
See the latest readings attached.