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user_srzp4c
1st Topic

6 Messages

Tuesday, June 11th, 2024 7:17 PM

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upstream power low

My upstream power is low according to my Netgear Cable Diagnostics.

All my cable connections are tight and I have no splitters.

What would be the cause of this? Is this on Xfinity's end?

Regards,

Gerald [Edited: "Personal Information"]

Question

 • 

Updated 

11 months ago

 • Edited

171

3

0

strykerzr350

Contributor

 • 

145 Messages

11 months ago

Can you copy and paste your modem logs?

35 to 48 is decent, anything higher or lower is bad.

42 to 46 is the sweet spot.

(edited)

1

0

user_srzp4c

6 Messages

Thanks for your response strykerz350.

Here's the cable diagnostics from my Netgear cable modem:

Cable Diagnostic

Status: Poor

Action: 
[Upstream Power Level]
Try these actions (Click the Refresh button after each step):
1) Make sure the coaxial cable is tightly connected.
2) Remove any unnecessary splitters.
3) Replace any required splitters.
4) Contact your service provider for troubleshooting help.

Internet Access: Good

Downstream Status: Good

    Downstream Power Level: Good

    Downstream SNR: Good

Upstream Status:  Poor

    Upstream Power Level: Poor
    Upstream power is poor (28.5dBmV). The recommended level is from 30 to 55dBmV.


Current time: Tue Jun 11 15:39:52 2024

Startup Procedure
Acquire Downstream Channel: 507 MHz   Locked
Connectivity State:          OK       Operational
Boot State:                  OK       Operational
Security:                   Enabled   BPI+


Downstream Bonded Channels
Channel LockedStatus Modulation ChannelID  Frequency        Power       SNR   Correctables Uncorrectables     
      1     Locked     256 QAM      5     507000000 Hz     -3.5 dBmV     42.4 dB     159     0
      2     Locked     256 QAM      1     477000000 Hz     -3.2 dBmV     42.6 dB     127     0
      3     Locked     256 QAM      2     483000000 Hz     -3.1 dBmV     42.7 dB     114     0
      4     Locked     256 QAM      3     489000000 Hz     -3.2 dBmV     42.7 dB     138     0
      5     Locked     256 QAM      4     495000000 Hz     -3.3 dBmV     42.6 dB     142     0
      6     Locked     256 QAM      6     513000000 Hz     -3.8 dBmV     42.4 dB     162     0
      7     Locked     256 QAM      7     519000000 Hz     -4 dBmV     42.3 dB     131     0
      8     Locked     256 QAM      8     525000000 Hz     -4.5 dBmV     42 dB     173     0
      9     Locked     256 QAM      9     531000000 Hz     -4.9 dBmV     41.8 dB     188     0
     10     Locked     256 QAM     10     537000000 Hz     -5.3 dBmV     41.6 dB     205     0
     11     Locked     256 QAM     11     543000000 Hz     -5.5 dBmV     41.5 dB     230     0
     12     Locked     256 QAM     12     549000000 Hz     -5.7 dBmV     41.3 dB     216     0
     13     Locked     256 QAM     13     555000000 Hz     -5.9 dBmV     41.2 dB     240     0
     14     Locked     256 QAM     14     561000000 Hz     -5.8 dBmV     41.2 dB     222     0
     15     Locked     256 QAM     15     567000000 Hz     -5.7 dBmV     41.3 dB     255     0
     16     Locked     256 QAM     16     573000000 Hz     -5.5 dBmV     41.4 dB     263     0
     17     Locked     256 QAM     17     579000000 Hz     -5.3 dBmV     41.4 dB     247     0
     18     Locked     256 QAM     18     585000000 Hz     -5.5 dBmV     41.3 dB     261     0
     19     Locked     256 QAM     19     591000000 Hz     -5.8 dBmV     41.1 dB     290     0
     20     Locked     256 QAM     34     453000000 Hz     -3.1 dBmV     42.9 dB     95     0
     21     Locked     256 QAM     35     459000000 Hz     -3.3 dBmV     42.9 dB     87     0
     22     Locked     256 QAM     36     465000000 Hz     -3.3 dBmV     42.8 dB     129     0
     23     Locked     256 QAM     37     471000000 Hz     -3.3 dBmV     42.8 dB     133     0
     24     Locked     256 QAM     38     405000000 Hz     -3.2 dBmV     43 dB     41     0
     25     Locked     256 QAM     39     411000000 Hz     -3.2 dBmV     42.9 dB     41     0
     26     Locked     256 QAM     40     417000000 Hz     -3.1 dBmV     43 dB     53     0
     27     Locked     256 QAM     41     423000000 Hz     -3 dBmV     43.1 dB     64     0
     28     Locked     256 QAM     42     429000000 Hz     -2.9 dBmV     43.1 dB     36     0
     29     Locked     256 QAM     43     435000000 Hz     -3 dBmV     43 dB     53     0
     30     Locked     256 QAM     44     441000000 Hz     -3.2 dBmV     42.9 dB     75     0
     31     Locked     256 QAM     45     447000000 Hz     -3.1 dBmV     42.9 dB     96     0
     32     Not Locked     Unknown      0     0 Hz     0.0     0.0     0     0


Upstream Bonded Channels
Channel   LockedStatus  ChannelType ChannelID   SymbolRate        Frequency       Power     
      1       Locked       ATDMA      7       5120 Ksym/sec       22800000 Hz       28.8 dBmV
      2       Locked       ATDMA      5       5120 Ksym/sec       35600000 Hz       30.3 dBmV
      3       Locked       ATDMA      6       5120 Ksym/sec       29200000 Hz       29.5 dBmV
      4       Locked       ATDMA      8       5120 Ksym/sec       16400000 Hz       28.5 dBmV
      5       Locked       ATDMA     10       1280 Ksym/sec       39600000 Hz       37.3 dBmV
      6       Not Locked       Unknown      0       0       0       0.0
      7       Not Locked       Unknown      0       0       0       0.0
      8       Not Locked       Unknown      0       0       0       0.0


Downstream OFDM Channels
Channel   LockedStatus  ProfileID  ChannelID    Frequency       Power       SNR/MER    ActiveSubcarrier    Unerror    Correctable   Uncorrectable
      1     Locked     0 ,1 ,2 ,3     29     690000000 Hz     -7.02 dBmV     39.2 dB     1228 ~ 2867     2736249764     2675645170     0
      2     Not Locked     0      0     0 Hz     0 dBmV     0 dB     0 ~ 4095     0     0     0


Upstream OFDMA Channels
Channel   LockedStatus    ProfileID    ChannelID    Frequency       Power
      1     Not Locked     0      0     0 Hz     0 dBmV
      2     Not Locked     0      0     0 Hz     0 dBmV


Event Log
         Time               Priority     Description
Tue Jun 11 02:11:25 2024     Critical     Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Mon Jun 10 15:34:25 2024     Notice     DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3.;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Mon Jun 10 15:34:15 2024     Notice     TLV-11 - unrecognized OID;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Thu Jan  1 00:01:03 1970     Notice     Honoring MDD; IP provisioning mode = IPv6
Thu Jan  1 00:00:57 1970     Critical     No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Thu Jan  1 00:00:53 1970     Critical     SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Sun Jun  9 19:48:20 2024     Critical     Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Fri Jun  7 22:04:00 2024     Critical     Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Thu Jun  6 17:59:23 2024     Critical     Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Thu Jun  6 08:42:37 2024     Critical     Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Wed Jun  5 20:08:07 2024     Critical     Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Mon Jun  3 19:50:40 2024     Critical     Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Thu Jan  1 00:01:12 1970     Critical     SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Thu Jan  1 00:00:58 1970     Critical     No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Thu Jan  1 00:00:54 1970     Critical     SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Thu Jan  1 00:00:57 1970     Critical     No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Thu Jan  1 00:00:53 1970     Critical     SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Sat Apr 20 10:53:30 2024     Critical     No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Sat Apr 20 10:53:25 2024     Critical     SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Sat Apr 20 10:48:38 2024     Critical     No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Wed Apr  3 08:17:47 2024     Critical     Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Tue Mar 26 20:30:41 2024     Critical     Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Fri Feb 16 13:10:19 2024     Critical     SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Fri Feb 16 13:10:13 2024     Critical     SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Fri Feb 16 13:10:08 2024     Critical     SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Fri Feb 16 13:09:53 2024     Critical     Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Thu Jan 18 21:27:33 2024     Critical     Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Thu Jan  4 09:01:02 2024     Critical     Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Thu Jan  1 00:00:49 1970     Critical     No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Thu Jan  1 00:00:43 1970     Critical     SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Thu Dec 28 00:01:38 2023     Critical     No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Thu Dec 28 00:01:32 2023     Critical     SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
Thu Jan  1 00:02:39 1970     Critical     SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Thu Jan  1 00:00:46 1970     Critical     SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;

(edited)

11 months ago

0

EG

Expert

 • 

110.2K Messages

11 months ago

Are you actually experiencing any connectivity problems ?

7

0

user_srzp4c

6 Messages

Hello EG,

Randomly the internet disconnects then reconnects.

I've power cycled the modem a few times but the cable diagnostics still shows an upstream power status of poor.

11 months ago

0

XfinityAldrik

Official Employee

 • 

2.1K Messages

Thank you for reaching out to us@user_srzp4c! When your internet disconnects, does it happen on all devices at the same time? Have you noticed if hardwired connections using an ethernet cable also lose connection?

I am an Official Xfinity Employee.
Official Employees are from multiple teams within Xfinity: CARE, Product, Leadership.
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Please, mark a reply as the Accepted Answer.tick

11 months ago

0

user_srzp4c

6 Messages

Hi,

It drops for all device on wi-fi.

None of my devices are hardwired to the modem.

A wi-fi signal strength shows good signal strength, so I know it's not the actual wifi.

I understand that low upstream signals can cause this. How can this be fixed?

Here's a cut and paste of the cable diagnostics from my modem:

...


Upstream Bonded Channels
Channel   LockedStatus  ChannelType ChannelID   SymbolRate        Frequency       Power     
      1       Locked       ATDMA      7       5120 Ksym/sec       22800000 Hz       28.8 dBmV
      2       Locked       ATDMA      5       5120 Ksym/sec       35600000 Hz       30.3 dBmV
      3       Locked       ATDMA      6       5120 Ksym/sec       29200000 Hz       29.5 dBmV
      4       Locked       ATDMA      8       5120 Ksym/sec       16400000 Hz       28.5 dBmV
      5       Locked       ATDMA     10       1280 Ksym/sec       39600000 Hz       37.3 dBmV
      6       Not Locked       Unknown      0       0       0       0.0
      7       Not Locked       Unknown      0       0       0       0.0
      8       Not Locked       Unknown      0       0       0       0.0

...

I understand it should be like the number 5 channel.

Thanks.

(edited)

11 months ago

0

user_srzp4c

6 Messages

User EG suggests I use a 9DB return path attenuator. Do you agree with this recommendation?

Thanks.

11 months ago

0

XfinityJustinC

Official Employee

 • 

1.2K Messages

@user_srzp4c an attenuator is a great way to help with power level output for modems. @EG is a very helpful expert of the Xfinity Forum community, and I trust his recommendations. 

Before purchasing the attenuator, we could run through some troubleshooting/signal testing as well to rule out anything signal wise from the area equipment to the home that could be causing issues. If you would like to run through troubleshooting with me, please let me know. 

I am an Official Xfinity Employee.
Official Employees are from multiple teams within Xfinity: CARE, Product, Leadership.
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Please, mark a reply as the Accepted Answer.tick

11 months ago

EG

Expert

 • 

110.2K Messages

11 months ago

@user_srzp4c 

You could try using a return path attenuator to raise the transmit power of the modem to help the signal to be higher than the noise floor. I would try using a 9 dB one and see. YMMV.

https://www.tonercable.com/product/rpa42-return-path-attenuator-3-6-9-12-15-db-values/ 

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