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Recognized Contributor
Bill-1948
Posts: 796
Registered: ‎06-03-2006

Motorola sb6120 problem

After Comcast went to $7.00 modem rental. I bought a Motrola sb6120, at Best Buy. Had a lot of problems getting to work,you know 800-comcast. Not a good number to call. After about 5 tries, it works. Not as good as the Comcast rental. The net says Comcast has had alot of problems with sb6120. After a bunch of repower,no better. Tried the reset to factory, speed still seems slow at times. enclosed is a copy of the modem log.

 

Downstream  Bonding Channel Value
Channel ID 3  
Frequency 423000000 Hz 
Signal to Noise Ratio 38 dB 
Downstream Modulation QAM256 
Power LevelThe Downstream Power Level reading is a snapshot taken at the time this page was requested. Please Reload/Refresh this Page for a new reading 
 8 dBmV  


Upstream  Bonding Channel Value
Channel ID 1  
Frequency 31500000 Hz 
Ranging Service ID 5736 
Symbol Rate 5.120 Msym/sec 
Power Level 41 dBmV 
Upstream Modulation [3] QPSK
[3] 64QAM
 
Ranging Status  Success 


Signal Stats (Codewords) Bonding Channel Value
Channel ID 3  
Total Unerrored Codewords 7755955163 
Total Correctable Codewords 1 
Total Uncorrectable Codewords 477 

 


--------------------------------------------------------------------------------
--------------------------------------------------------------------------------


Time Priority Code Message
Feb 09 2011 22:36:05 3-Critical R02.0 No Ranging Response received - T3 time-out;CM-MAC=00:23:74:f2:51:43;CMTS-MAC=00:09:7b:8b:40:ce;CM-QOS=1.1;CM-VER=3.0;

 

-------------------------------------------------------------------------------
Model Name: SB6120
Vendor Name: Motorola
Firmware Name: SB612X-1.0.3.3-SCM00-NOSH
Boot Version: PSPU-Boot 1.0.0.4m1
Hardware Version: 3.0
Serial Number:
Firmware Build Time: Aug 12 2010 13:58:19

 

800-comcast says no problem What know.

Connection Expert
EG
Posts: 42,451
Registered: ‎12-24-2003

Re: Motorola sb6120 problem

[ Edited ]

In what way exactly do you mean "its not as good as the CC rental" ? Your signal stats and codeword data are stellar with it. I've used one for almost a year and it been a solid performer. Best modem I've ever had !

 

[EDIT]

 

O/k now I see you mean the speeds. I'd say there is something else going on. Maybe an intermittent upstream channel noise ingress or a traffic/congestion issue especially since you state "at times".

Recognized Contributor
Bill-1948
Posts: 796
Registered: ‎06-03-2006

Re: Motorola sb6120 problem

I had to spend a lot of time and about 4 or 5 tries get it running,two phone calls to 800-comcast. As i have said before,not a fan of Comcast. Based on past experience. Is it ok, to doughty what Comcast cc says?

Connection Expert
EG
Posts: 42,451
Registered: ‎12-24-2003

Re: Motorola sb6120 problem

Well there were indeed some "provisioning" issues with certain CMTS's and earlier versions of firmware combinations but I believe that these are now rectified. These were not issues of a "performance" nature. There are two additional signal stats which can't be read at the modem level. They can only be read from their end by them polling the CMTS (Cable Modem Termination System) at the local headend facility. They are the 'Upstream Receive Power Level' and the 'Upstream uSNR' (Signal To Noise Ratio). Both of these are as equally important in diagnosing connectivity issues as are the modem's stats. You can call in and ask what these figures are. The Upstream Receive Power Level should fall within the range of -10dB to +10dB with 0dB being in the middle and perfect. The Upstream SNR should be least 30dB, and the higher it is the better. You could have a noise ingress issue in the upstream channel as I earlier stated.

New Visitor
bkushner
Posts: 3
Registered: ‎02-15-2011

Re: Motorola sb6120 problem

Hey I thought I was reading my OWN story here.

 

Same deal..bought the 6120 on Amazon 2 weeks ago after seeing the price increase. I had no problem getting the modem up and running but had many problems with download and upload stream. I have EXTREME 50 and was getting 25 /3. Also noticed that when I would visit a web page, there would be like a 1-2 second delay before the page started to load..Hesitiation is the best word, maybe skipping.

 

Finally had enough, rehooked my UBEE modem (which I hadn't returned yet) called Comcast and changed back. Hesitation stopped, speeds solid 60/7 (6PM) and I notice an all round sense of greater speed.

 

The tech on the phone said they have a lot of problems with the 6120. One thing he mentioned was since so many are using the COMCAST modem the techs fine tune that modem and dont do much with the others.

 

My question is can I buy my current Ubee modem on the open market?

Connection Expert
EG
Posts: 42,451
Registered: ‎12-24-2003

Re: Motorola sb6120 problem

[ Edited ]

bkushner wrote:

 

One thing he mentioned was since so many are using the COMCAST modem the techs fine tune that modem and dont do much with the others.

 

 

No such animal, sorry. Tech was talkin' carp like so many do...


 

 

Recognized Contributor
Bill-1948
Posts: 796
Registered: ‎06-03-2006

Re: Motorola sb6120 problem

Here is my modem log as of this day:

Jan 01 1970 00:00:36 5-Warning T202.0 Lost MDD Timeout;CM-MAC=00:23:74:f2:51:43;CMTS-MAC=00:09:7b:8b:40:ce;CM-QOS=1.1;CM-VER=3.0; Jan 01 1970 00:00:18 5-Warning T203.0 MDD message timeout;CM-MAC=00:23:74:f2:51:43;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0; Jan 01 1970 00:00:12 6-Notice   Cable Modem Reboot due to power reset ;CM-MAC=00:23:74:f2:51:43;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0; Jan 01 1970 00:00:36 5-Warning T202.0 Lost MDD Timeout;CM-MAC=00:23:74:f2:51:43;CMTS-MAC=00:09:7b:8b:40:ce;CM-QOS=1.1;CM-VER=3.0; Jan 01 1970 00:00:18 5-Warning T203.0 MDD message timeout;CM-MAC=00:23:74:f2:51:43;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0; Jan 01 1970 00:00:12 6-Notice   Cable Modem Reboot due to power reset ;CM-MAC=00:23:74:f2:51:43;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0; Jan 01 1970 00:00:18 5-Warning T203.0 MDD message timeout;CM-MAC=00:23:74:f2:51:43;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0; Jan 01 1970 00:00:12 6-Notice   Cable Modem Reboot due to power reset ;CM-MAC=00:23:74:f2:51:43;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0; Jan 01 1970 00:00:36 5-Warning T202.0 Lost MDD Timeout;CM-MAC=00:23:74:f2:51:43;CMTS-MAC=00:09:7b:8b:40:ce;CM-QOS=1.1;CM-VER=3.0; Jan 01 1970 00:00:18 5-Warning T203.0 MDD message timeout;CM-MAC=00:23:74:f2:51:43;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0; Jan 01 1970 00:00:12 6-Notice   Cable Modem Reboot due to power reset ;CM-MAC=00:23:74:f2:51:43;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0; Feb 11 2011 10:56:21 3-Critical R02.0 No Ranging Response received - T3 time-out;CM-MAC=00:23:74:f2:51:43;CMTS-MAC=00:09:7b:8b:40:ce;CM-QOS=1.1;CM-VER=3.0; Jan 01 1970 00:01:00 5-Warning T202.0 Lost MDD Timeout;CM-MAC=00:23:74:f2:51:43;CMTS-MAC=00:09:7b:8b:40:ce;CM-QOS=1.1;CM-VER=3.0; Jan 01 1970 00:00:42 5-Warning T203.0 MDD message timeout;CM-MAC=00:23:74:f2:51:43;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0; Jan 01 1970 00:00:12 6-Notice   Cable Modem Reboot due to power reset ;CM-MAC=00:23:74:f2:51:43;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0; Feb 10 2011 20:17:07 3-Critical R02.0

No Ranging Response received - T3 time-out;CM-MAC=00:23:74:f2:51:43;CMTS-MAC=00:09:7b:8b:40:ce;CM-QOS=1.1;CM-VER=3.0;

 

Why so many errors showing up. I did not put 1 thing orginal post i should have, MY BAD! Had 2 grands that day was a snow day,some what busy that day.

 

Our (world of more) was to happen(for the third time) on 02/08/11. This per our local news paper. No change yet.  I thank this is on the tv side,not hsi. They may have been working on the system.(I hope)

Not a rant,just think comcast miss spoke agin.

 Sorry about the big gap in post.

Thanks 

 

 

Connection Expert
EG
Posts: 42,451
Registered: ‎12-24-2003

Re: Motorola sb6120 problem

The formatting on that log is very hard to read. :smileysad:

Recognized Contributor
Bill-1948
Posts: 796
Registered: ‎06-03-2006

Re: Motorola sb6120 problem

    5-Warning T202.0 Lost MDD Timeout;CM-MAC=00:23:74:f2:51:43;CMTS-MAC=00:09:7b:8b:40:ce;CM-QOS=1.1;CM-VER=3.0;

 

5-Warning T203.0 MDD message timeout;CM-MAC=00:23:74:f2:51:43;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0;

6-Notice   Cable Modem Reboot due to power reset ;CM-MAC=00:23:74:f2:51:43;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0;

 

5-Warning T202.0 Lost MDD Timeout;CM-MAC=00:23:74:f2:51:43;CMTS-MAC=00:09:7b:8b:40:ce;CM-QOS=1.1;CM-VER=3.0;

 

Warning T203.0 MDD message timeout;CM-MAC=00:23:74:f2:51:43;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0;

 

6-Notice   Cable Modem Reboot due to power reset ;CM-MAC=00:23:74:f2:51:43;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0;

 

Warning T203.0 MDD message timeout;CM-MAC=00:23:74:f2:51:43;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0;

 

6-Notice   Cable Modem Reboot due to power reset ;CM-MAC=00:23:74:f2:51:43;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0;

 

-Warning T202.0 Lost MDD Timeout;CM-MAC=00:23:74:f2:51:43;CMTS-MAC=00:09:7b:8b:40:ce;CM-QOS=1.1;CM-VER=3.0;

 

5-Warning T203.0 MDD message timeout;CM-MAC=00:23:74:f2:51:43;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0; -Notice   Cable Modem Reboot due to power reset ;CM-MAC=00:23:74:f2:51:43;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0;

 

3-Critical R02.0 No Ranging Response received - T3 time-out;CM-MAC=00:23:74:f2:51:43;CMTS-MAC=00:09:7b:8b:40:ce;CM-QOS=1.1;CM-VER=3.0;

 

Jan 01 1970 00:01:00 5-Warning T202.0 Lost MDD Timeout;CM-MAC=00:23:74:f2:51:43;CMTS-MAC=00:09:7b:8b:40:ce;CM-QOS=1.1;CM-VER=3.0;

 

Jan 01 1970 00:00:42 5-Warning T203.0 MDD message timeout;CM-MAC=00:23:74:f2:51:43;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0;

 

Jan 01 1970 00:00:12 6-Notice   Cable Modem Reboot due to power reset ;CM-MAC=00:23:74:f2:51:43;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.0;

 

Feb 10 2011 20:17:07 3-Critical R02.0 No Ranging Response received - T3 time-out;CM-MAC=00:23:74:f2:51:43;CMTS-MAC=00:09:7b:8b:40:ce;CM-QOS=1.1;CM-VER=3.0;

 

My know how on copy,paste,change size is not good. We took a shot at it.

 

Thanks

 

   

Regular Visitor
Posts: 1
Registered: ‎07-18-2009

Re: Motorola sb6120 problem

Wow.   Exact same problem here.  Bought a SB6120.  Uploads speeds are horrible.   Sometimes it will throttle down to 21k/sec after starting at 260k/sec.    I disconnected my router, and plugged straight into the SB6120 with the same results.

 

Returned my old modem, so I can't plug it back in.    

 

Spent 30 mins with a tech today - she was tech savvy, but didn't have any idea why the U/L was so bad.   

 

Any more updates on this problem?

Recognized Contributor
Bill-1948
Posts: 796
Registered: ‎06-03-2006

Re: Motorola sb6120 problem

Still have no responce on last post. Our upgrade they said would happen happen in 02/2011 and 2 times in 2010, not here yet. Thought that might part of my problem. Maybe some of the experts here will update us  Called 1-800-(wait for ever) comcast,they said looks good to them. Mabye my problem is part of there upgrade. Hope so! The net says Comcast is haveing a lot of problems with the SB2160 modem. Maby they get things up and running,soon i hope

New Visitor
bkushner
Posts: 3
Registered: ‎02-15-2011

Re: Motorola sb6120 problem

I had a tech come out again today. He finally spoke to someone in engineering. He tells me the problem where I'm at in Audubon NJ should be corrected when they finally move my area to all digital which is scheduled in early March. Supposedly this will free up space they need to bond uploaded stream, currently only DL is bonded.

 

Sounds plausible for now or could be complete b ull.

 

I'm extreme 50 and consistantly get 60 DL and 4-5UP

 

When I had my 6120 hooked up singnals were sputtering and all over the place.

New Visitor
singlewall
Posts: 1
Registered: ‎08-06-2011

Re: Motorola sb6120 problem

Same issue here...with the leased modem and Ultra22! service I was getting 32 down and 8 up.  With my new Surfboard (purchsed from Amazon) I am now getting results all over the place, with the best case being around 30 down and 2 up.  Ive noticed from one test to the next my ping will jump from 10ms to 200+ms and my download speeds will drop from 30mb to maybe 5mb.  The only thing that changed in my configuration is the modem - and the issue happens whether or not I am going through my router.

 

Tech is coming out tomorrow to look at the problem - I will post an update here once they have had a chance to look at the problem just in case anyone else runs into this issue.

New Visitor
Posts: 2
Registered: ‎12-13-2007

Re: Motorola sb6120 problem

Connected SB6120, could not establish internet connection. Called 1-800-comcast. Tech tried for over an hour. No connection. She seemed knowledgable, said that SB6120 usually difficult to establish connect, often takes 30+ mins. This time over an hour & nada.............. Sending it back to Amazon in the AM. Any reccomendations for a 3.0 modem?

Contributor
killahbeatz
Posts: 9
Registered: ‎07-29-2011

Re: Motorola sb6120 problem

I have the same problem too.The problem is that customer owned sb6120 are not being set up to channel bound so you get slower speeds from a customer owned sb6120 then you would from a comcast rented sb6120 that is channel bonding and running dosis 3. If your modem online light is green (not the link light) then you are not running channel bonding. The online light would be blue if it were channel bonding ( a blue link light just means Gigabit Ethernet connection). If you were running docsis 3 it would have four Downstream  Bonding Channel Value on the modem admin page but you have only one. I have tried to contact comcast adout this but it seem like I am getting the chase around. There seem to be some people that have got it to work I just dont know how or to whom to talk to at comcast that could fix this problem

Connection Expert
EG
Posts: 42,451
Registered: ‎12-24-2003

Re: Motorola sb6120 problem


killahbeatz wrote:

I have the same problem too.The problem is that customer owned sb6120 are not being set up to channel bound so you get slower speeds from a customer owned sb6120 then you would from a comcast rented sb6120 that is channel bonding and running dosis 3. 


That is so not true. A D3 capable modem on a upgraded to D3 CMTS wiil lock on to any and all avaIable multiple bonded channels regardless of any "setup"/intervention by a CSR, or owned or not owned modem...

Contributor
killahbeatz
Posts: 9
Registered: ‎07-29-2011

Re: Motorola sb6120 problem

Sorry if my facts are wrong  I want to fix this problem and not add to it. I have a sb6120 that is not channel bonding. I live in a upgraded area and the CSR has acknowledgedthat  I am in spec but I dont have any bonding.I have seached for this online and it seems to effect other people with customer owned 6120 so I am thinking that it not getting provision right or it a problem with the firmware or my CMTS but what ever it is It needs to get this fixed

Regular Contributor
jazzy007
Posts: 30
Registered: ‎08-14-2011

Re: Motorola sb6120 problem

[ Edited ]

EG wrote:

killahbeatz wrote:

I have the same problem too.The problem is that customer owned sb6120 are not being set up to channel bound so you get slower speeds from a customer owned sb6120 then you would from a comcast rented sb6120 that is channel bonding and running dosis 3. 


That is so not true. A D3 capable modem on a upgraded to D3 CMTS wiil lock on to any and all avaIable multiple bonded channels regardless of any "setup"/intervention by a CSR, or owned or not owned modem...


Agreed with EG. See my Amazon purchased 6120 with bonding on both DS & US, just installed this month.

 



Downstream Bonding Channel Value
Channel ID
Frequency735000000 Hz 741000000 Hz 747000000 Hz 759000000 Hz 
Signal to Noise Ratio35 dB 35 dB 35 dB 36 dB 
Downstream ModulationQAM256 QAM256 QAM256 QAM256 
Power Level
The Downstream Power Level reading is a snapshot taken at the time this page was requested. Please Reload/Refresh this Page for a new reading
4 dBmV  3 dBmV  3 dBmV  3 dBmV  

 

Upstream Bonding Channel Value
Channel ID
Frequency30600000 Hz 25300000 Hz 37000000 Hz 
Ranging Service ID6483 6483 6483 
Symbol Rate5.120 Msym/sec 2.560 Msym/sec 5.120 Msym/sec 
Power Level48 dBmV 47 dBmV 48 dBmV 
Upstream Modulation[3] QPSK
[3] 64QAM
 
[3] QPSK
[2] 16QAM
 
[3] QPSK
[3] 64QAM
 
Ranging StatusSuccess Success Success 
Cable Expert
i-am-nerdburg
Posts: 11,209
Registered: ‎06-27-2009

Re: Motorola sb6120 problem


killahbeatz wrote:

Sorry if my facts are wrong  I want to fix this problem and not add to it. I have a sb6120 that is not channel bonding. I live in a upgraded area and the CSR has acknowledgedthat  I am in spec but I dont have any bonding.


The customer service reps (sadly) are prob not the best source of info. You can live in an upgraded Xfinity system and not have upstream bonding. Most likely your system simply hasn't been upgraded yet. And does it matter that much?

Contributor
killahbeatz
Posts: 9
Registered: ‎07-29-2011

Re: Motorola sb6120 problem

[ Edited ]

 what firmware do you have also I read that Comcast has been having problems with sb6120 and some of there CMTS You can find out what your CMTS you have by looking up CMTS mac address on the sb6120 logs and going to this site http://www.coffer.com/mac_find/   Also I use too get the channel bonding were I lived a block away from my current address with a Comcast modem. So I know its in my area. My current address show on Comcast as being an upgraded area. Im current getting 4 Mbps  because I am not running dosis 3. I should be happy for this speed as I don't get connection lost but I am not as I choose Comcast as my internet provider over dsl cheaper rates because of the advertized 12 Mbps. I got the sb6120 to take advantage of this upgrade

Any help or info from anyone would be helpful 

 

My firmware is SB612X-1.0.3.3-SCM00-NOSH

My CMTS is 002584 Cisco Systems

 

Downstream     Bonding Channel Value
Channel ID     37
Frequency     627000000 Hz
Signal to Noise Ratio     36 dB
Downstream Modulation     QAM256
Power Level
The Downstream Power Level reading is a snapshot taken at the time this page was requested. Please Reload/Refresh this Page for a new reading
    -2 dBmV 

Upstream     Bonding Channel Value
Channel ID     4
Frequency     30000000 Hz
Ranging Service ID     4991
Symbol Rate     5.120 Msym/sec
Power Level     51 dBmV
Upstream Modulation     [3] QPSK
[3] 32QAM
 
Ranging Status     Success

Signal Stats (Codewords)     Bonding Channel Value
Channel ID     37
Total Unerrored Codewords     2860785635
Total Correctable Codewords     82
Total Uncorrectable Codewords     1375


 

 

Regular Contributor
jazzy007
Posts: 30
Registered: ‎08-14-2011

Re: Motorola sb6120 problem


killahbeatz wrote:

jazzy007 what firmware do you have also I read that Comcast has been having problems with sb6120 and some of there CMTS You can find out what your CMTS you have by looking up CMTS mac address on the sb6120 logs and going to this site http://www.coffer.com/mac_find/ 



Firmware Name: SB612X-1.0.3.3-SCM00-NOSH
CMTS:
00015CCADANT INC.
New Visitor
mazar
Posts: 2
Registered: ‎08-19-2011

Re: Motorola sb6120 problem

I replaced my Linksys CM100 with Motorola SB6120 yesterday with the hopes of getting better performance. I wish I had not done it. My CM100 could do 22 down 4 up, but SB6120 can only do 20 down 1 up. 

Called Comcast and they said they cannot do anything. What a shame!

I diched comcast TV for poor service, but had to stick with Internet because did not have any other alternative. I cannot believe I'm paying $60 a month for this!

Regular Contributor
jazzy007
Posts: 30
Registered: ‎08-14-2011

Re: Motorola sb6120 problem


mazar wrote:

I replaced my Linksys CM100 with Motorola SB6120 yesterday with the hopes of getting better performance. I wish I had not done it. My CM100 could do 22 down 4 up, but SB6120 can only do 20 down 1 up. 


I am getting solid 24/4 on my 6120 so far. Unless you have a lemon, not sure 6120 is always bad.

I do realize 6120, maybe D3 modem in general has tighter ideal operational range. If your old D1/D2 modem has been working on the edge of operational range, it might continue working without any issue, but 6120 or maybe D3 modem in general, might need to bring PWR/SNR/Received-Level on both DS/US to more closer ideal value.

 

So post your ds/us power/snr/received-level might help.

New Visitor
mazar
Posts: 2
Registered: ‎08-19-2011

Re: Motorola sb6120 problem

[ Edited ]

Hers is the data:



Downstream                      Bonding Channel Value

Channel ID                     1                     2                      3                     4

Frequency                      681000000 Hz     687000000 Hz     693000000 Hz     699000000 Hz

Signal to Noise Ratio        35 dB                36 dB                36 dB                36 dB

Downstream Modulation     QAM256             QAM256             QAM256             QAM256

Power Level                    -6 dBmV            -6 dBmV            -6 dBmV            -6 dBmV

 

Upstream                       Bonding Channel Value

Channel ID                 6

Frequency                   29900000 Hz

Ranging Service ID       409

Symbol Rate               5.120 Msym/sec

Power Level                52 dBmV

Upstream Modulation     [3] QPSK
[3] 64QAM

Ranging Status            Success

 

Signal Stats (Codewords)           Bonding
Channel Value

Channel ID                              1                   2                   3                   4

Total Unerrored Codewords          2726998776     2726998584      2726998508     2726999011

Total Correctable Codewords        551                280                308                404

Total Uncorrectable Codewords         5007      5048      5233      4760

Regular Contributor
jazzy007
Posts: 30
Registered: ‎08-14-2011

Re: Motorola sb6120 problem


mazar wrote:

Hers is the data:

 

Downstream                      Bonding Channel Value

Channel ID                     1                     2                      3                     4

Frequency                      681000000 Hz     687000000 Hz     693000000 Hz     699000000 Hz

Signal to Noise Ratio        35 dB                36 dB                36 dB                36 dB

Downstream Modulation     QAM256             QAM256             QAM256             QAM256

Power Level                    -6 dBmV            -6 dBmV            -6 dBmV            -6 dBmV

 

Upstream                       Bonding Channel Value

Channel ID                 6

Frequency                   29900000 Hz

Ranging Service ID       409

Symbol Rate               5.120 Msym/sec

Power Level                52 dBmV

Upstream Modulation     [3] QPSK
[3] 64QAM

Ranging Status            Success

 

Signal Stats (Codewords)           Bonding
Channel Value

Channel ID                              1                   2                   3                   4

Total Unerrored Codewords          2726998776     2726998584      2726998508     2726999011

Total Correctable Codewords        551                280                308                404

Total Uncorrectable Codewords         5007      5048      5233      4760


Your downstream power received is a little low, but most important upstream transmit power is a little too high, hence your modem is working very hard to sync with headend at al time. It will be interesting to call Comcast & find out what is your upstream power received at headend & SNR at headend.

Do you have splitter or splitters in your house? If yes & if it is possible, it is worth to check them out, maybe remove them temporary just to understand any of them are create significant attenuation/noise.

Both correctable/uncorrectable codewords are high, but it is how often they change really matter.

One thing you could try is reboot/power-cycle modem, & record correctable/uncorrectable values as soon as modem/router is up & running & can connect to internet, & then monitoring them. If they continue increase rapidly, call Comcast.

My own short experience with 6120 is it work very well when operating in close to ideal value on both US/DS, included power transmit/receive & SNR level, but once it is operating on the edge, it does not do very well.

Contributor
slswyoming
Posts: 12
Registered: ‎08-20-2011

Re: Motorola sb6120 problem

[ Edited ]

My rented modem is a 5120, and no better.  Every day when I leave home, I unplug the surge protecter that powers my computer, monitor, wireless router.  I do that for lightning protection, and I also unplug the ethernet cable from the wireless router, so there is no lightning path.  The stuff that belongs to comcast, cable boxes and modem, are left plugged in and turned on.  I've been doing this for YEARS, and every where I have lived, including a small island in Caribbean, when I would come home and turn the computer back on, I would INSTANTLY have internet access. 

 

Well, NO, NO, NO, NOT COMCAST!!!  I have to play pluggy, un-pluggy with the router, the modem EVERY DAY to get my internet working.  This service SUCKS.

 

An hour ago I sat down with hot lunch to watch the last issue of Burn Notice I missed.... "err - call 1-800 comcast"   Long story short, if I have NOT used 'on demand' in a while (in this case, 5 days), it gets DEACTIVATED and must be REACTIVATED in order to watch!  This is the exact words of the technician on the phone.  Is this SERVICE?  To have what you are paying for UNAVAILABLE over and over and over again week after week?  How much are paying in bribes to politicians to be a provider?  This is NOT service, and is NOT going to get $89/month from me, not even hd, just internet and two tvs and basic.

New Visitor
ushaalladi
Posts: 1
Registered: ‎08-29-2011

Re: Motorola sb6120 problem

i too have the same problem, had troubleshoot with comcast CC dint help much, i had a troubleshoot with Motorola they said everything look good i cant return this modem since i purcashed it 4 months back, struggled a lot download speed is 0.30 mbps and upload 0.07 mbps i have invested 80$ on this motorola SB 6120 Docsis 3.0, i rented another modem again from comcast today, my internet speed is good 17mbps download 4.2 upload, please help with sb6120 problem

Cable Expert
i-am-nerdburg
Posts: 11,209
Registered: ‎06-27-2009

Re: Motorola sb6120 problem


bkushner wrote:

 

I'm extreme 50 and consistantly get 60 DL and 4-5UP

 

 


I'm in the same boat as you and get about the same speed. My upload is generally around 5 (sustained) and my download is 50+ sustained. When upstream bonding hits us, we will see a significant improvement in return path speed.

New Visitor
Chantling
Posts: 1
Registered: ‎09-20-2011

Re: Motorola sb6120 problem

Just out of curiosity, is the upload speed okay if there's absolutely nothing downloading?  I'm a Comcast field tech, and I've run into the situation you guys are experiencing a few times now.  The first time we replaced the entire drop system for the customer and pretty much their leg of the node over a period of several weeks, to no avail.  They had a 6120, and they were losing connection several times a day, usually around noon.  Nobody else in the neighborhood had the issue, signal was perfect in every respect, and we could never catch the problem to determine what was causing it.  They had returned their first 6120 because of the issue and had the same problem with the second, so we didn't try putting in a rental until we'd exhausted all other options.  They called Motorola, who confirmed there are issues with the 6120 and Comcast and recommended they exchange it for a 6121.  Cleared up their issue.  I don't know if their upload speeds suffered, but they haven't called back in ~3 months.

The most recent customer had a 6120, was losing connection as well as having upload speed problems, and replaced it with a 6121 after reading about the 6120 issues online.  The 6121 cured the disconnect issue, but continued to have upload speed issues.  When running a speed test with nothing being downloaded, his ul speed was around 4.4Mbps.  Go to youtube and download a 720p video while running the speedtest, and it would pause for maybe 10 seconds before starting the ul portion of the test, which started around 0.7 and ramped up to maybe 3.5Mbps.  1080p movies might mean you're waiting for several minutes before the test starts.  Sustained uploads, such as streaming video, averaged around 0.7Mbps when downloading was occurring.

His signal was perfect.  Up and downstream SNR, forward and return signal levels, receive at the CMTS, MER and BER; all were exactly where we want them.  No ingress whatsoever on the house's drop system, and no (measurable) ingress back to the node.  Maintenance crews were called out a total of 4 times that I'm aware of, possibly more, and the node was swept forward and return each time with no problem found.  All amplifiers on his leg of the node were replaced, just in case.  No packet loss; I ran 12000 packets at the tap and 11000 behind the modem, with 0 lost packets, which is pretty astonishing in itself.  Latency was fantastic every time tested.  Upload throughput on my signal meter was 6.6Mbps.  None of the other 150 or so internet or CDV customers in that node were calling in with multiple repeat HSI issues, nor was there an overabundance of calls in general.  As much as people enjoy bashing Comcast and all of their "stupid techs" who know nothing and don't care about their service, the majority of us do know our jobs and perform them well.  There was absolutely no signal issue at this house for us to repair, no aspect that we overlooked. When I finally got the call, I had one of our modems placed on a test account and took it out there.  Upload speeds were good no matter what we downloaded.

My point is that your ul speed problems, as well as connection issues with the 6120, may very well not be connected to a signal issue.  While I obviously can't unequivocally state that none of you have signal issues, I can say that this issue is definitely not confined to homes with signal problems.  A downstream receive of -6db is not going to cause any issues for you if it's caused by passive loss and not a damaged drop or a bad splitter, nor is an upstream of 52db.  54db is the magic number, because most modems' max transmit is either 54 or 57.  If the actual required upstream tx is higher than the modem's, the modem can't compensate and receive power at the CMTS begins to drop from the ideal of 0db.  At 52db, your modem's probably not maxed, you're hitting the CMTS at 0, and you've got 2-5db left in the modem, along with a couple of db of wiggle room with most CMTS'.  Certainly doesn't give you much leeway for signal fluctuation and we'd like it lower for that reason, but in many house setups, the only way to lower that upstream would be to run a dedicated outlet for the modem, and Comcast isn't going to pay for that.  Inside wires are the homeowner's property and responsiblity.  If you're concerned about your signal, then set up a service call and have the tech check the quality.  If he says everything's good, it's probably safe to believe him.  Field techs are not going to be able to fix your issue at that point.

Unfortunately, I don't have a solution for you, other than use a different modem.  But I am curious about whether your speeds change dramatically depending upon whether you're downloading or not.  I've been trying to get some info to give one of my headend techs about it.  I didn't think to ask the last customer if we could leave him a rental at no charge for a while and borrow his modem for the headed to test until after he'd replaced it.

As an aside, there is no "tuning" the signal for a given modem.  The signal is good or it's not.  There is no configuring your modem to channel bond on our part.  The channels are available in D3 systems for modems to bond or not as their capability allows.  And slswyoming, On Demand does not have to be reactivated constantly.  If the CAE really told you that, they were mistaken.  While it may be marginally satisfying to rage about Comcast's horrible service here, setting up a service call to fix the issue you obviously have will probably prove more effective at solving it in the long run.

Cable Expert
i-am-nerdburg
Posts: 11,209
Registered: ‎06-27-2009

Re: Motorola sb6120 problem


i-am-nerdburg wrote:

bkushner wrote:

 

I'm extreme 50 and consistantly get 60 DL and 4-5UP

 

 


I'm in the same boat as you and get about the same speed. My upload is generally around 5 (sustained) and my download is 50+ sustained. When upstream bonding hits us, we will see a significant improvement in return path speed.


Update: ComcastSteve worked his magic and my upload is back at 11+.

Connection Expert
EG
Posts: 42,451
Registered: ‎12-24-2003

Re: Motorola sb6120 problem


i-am-nerdburg wrote:

Update: ComcastSteve worked his magic and my upload is back at 11+.


What did he do nerd ? Switch your return carrier to a 64 QAM 5.120 Msym/sec one ?

Cable Expert
i-am-nerdburg
Posts: 11,209
Registered: ‎06-27-2009
Connection Expert
EG
Posts: 42,451
Registered: ‎12-24-2003

Re: Motorola sb6120 problem

Hope that it holds up for you ! DCC's are ever present..

Contributor
rgar98
Posts: 7
Registered: ‎09-12-2011

Re: Motorola sb6120 problem

How do you access SB6120 statistics/log?

 

Thanks.

 

RG

Cable Expert
i-am-nerdburg
Posts: 11,209
Registered: ‎06-27-2009