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I purchased a new SB8200 to upgrad from 500 mbps to Cox Gigablast internet.  This modem is on Cox’s approved list for Gigablast internet. Cox tech support provisioned the modem but speeds remained at 500 mbps. A technician was sent to the house.  The technician ran new cable from the street to the house and confirmed that 1.1 gig was arriving to the modem, but only 500 mbps coming from the modem.  Technician performed multiple resets, hard resets, and provisions with no success. Cox is now blaming the modem for the issue. I’m skeptical.  Any help you can provide would be appreciated. Modem diagnostics below. The event log shows occasional DHCP renewal failures and CM Status msg 16 and 24. 

SB8200Logout

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Connection

The status listed show the connection state of the cable modem. They are used by your service provider to evaluate the operation of the cable modem.

Startup Procedure
Procedure Status Comment
Acquire Downstream Channel 807000000 Hz Locked
Connectivity State OK Operational
Boot State OK Operational
Configuration File OK  
Security Enabled BPI+
DOCSIS Network Access Enabled Allowed  

 

Downstream Bonded Channels
Channel ID Lock Status Modulation Frequency Power SNR/MER Corrected Uncorrectables
5 Locked QAM256 807000000 Hz -7.4 dBmV 37.6 dB 231 58
1 Locked QAM256 783000000 Hz -6.2 dBmV 38.6 dB 66940 143003
2 Locked QAM256 789000000 Hz -7.0 dBmV 38.1 dB 53 0
3 Locked QAM256 795000000 Hz -6.4 dBmV 38.4 dB 0 0
4 Locked QAM256 801000000 Hz -7.1 dBmV 37.8 dB 0 0
6 Locked QAM256 813000000 Hz -5.8 dBmV 38.6 dB 264 1338
7 Locked QAM256 819000000 Hz -5.9 dBmV 38.7 dB 0 0
8 Locked QAM256 825000000 Hz -6.9 dBmV 37.9 dB 0 0
9 Locked QAM256 831000000 Hz -7.3 dBmV 37.7 dB 0 0
10 Locked QAM256 837000000 Hz -7.7 dBmV 37.4 dB 38 0
11 Locked QAM256 843000000 Hz -7.3 dBmV 37.6 dB 0 0
12 Locked QAM256 849000000 Hz -7.4 dBmV 37.5 dB 7 0
13 Locked QAM256 855000000 Hz -8.1 dBmV 37.1 dB 15 0
14 Locked QAM256 861000000 Hz -7.1 dBmV 37.8 dB 11 0
15 Locked QAM256 867000000 Hz -7.4 dBmV 37.5 dB 0 0
16 Locked QAM256 873000000 Hz -7.1 dBmV 37.7 dB 0 0
17 Locked QAM256 879000000 Hz -6.9 dBmV 38.0 dB 0 0
18 Locked QAM256 885000000 Hz -7.6 dBmV 37.2 dB 0 0
19 Locked QAM256 891000000 Hz -7.9 dBmV 36.9 dB 1 0
20 Locked QAM256 897000000 Hz -8.0 dBmV 36.9 dB 2 0
21 Locked QAM256 903000000 Hz -7.4 dBmV 37.2 dB 0 0
22 Locked QAM256 909000000 Hz -7.6 dBmV 37.0 dB 0 0
23 Locked QAM256 915000000 Hz -8.2 dBmV 36.6 dB 3 0
24 Locked QAM256 921000000 Hz -7.1 dBmV 37.6 dB 0 0
25 Locked QAM256 927000000 Hz -7.4 dBmV 37.3 dB 0 0
26 Locked QAM256 933000000 Hz -7.0 dBmV 37.6 dB 0 0
27 Locked QAM256 939000000 Hz -6.6 dBmV 37.7 dB 0 0
28 Locked QAM256 945000000 Hz -7.7 dBmV 36.9 dB 1 0
29 Locked QAM256 951000000 Hz -7.5 dBmV 37.1 dB 0 0
30 Locked QAM256 957000000 Hz -8.1 dBmV 36.7 dB 0 0
31 Locked QAM256 963000000 Hz -8.1 dBmV 36.8 dB 0 0
32 Locked QAM256 969000000 Hz -7.4 dBmV 37.3 dB 0 0
159 Locked Other 300000000 Hz 0.4 dBmV 34.2 dB 4055675631 6276

 

 

Upstream Bonded Channels
Channel Channel ID Lock Status US Channel Type Frequency Width Power
1 1 Locked SC-QAM Upstream 17600000 Hz 6400000 Hz 33.0 dBmV
2 2 Locked SC-QAM Upstream 24000000 Hz 6400000 Hz 33.0 dBmV
3 3 Locked SC-QAM Upstream 30400000 Hz 6400000 Hz 33.0 dBmV
4 4 Locked SC-QAM Upstream 36800000 Hz 6400000 Hz 34.0 dBmV
5 5 Locked SC-QAM Upstream 43200000 Hz 6400000 Hz 33.0 dBmV
6 6 Locked SC-QAM Upstream 67000000 Hz 6400000 Hz 36.0 dBmV
7 7 Locked SC-QAM Upstream 74000000 Hz 6400000 Hz 37.0 dBmV
8 8 Locked SC-QAM Upstream 81000000 Hz 6400000 Hz 36.0 dBmV

 

 

Current System Time: Mon Feb 13 12:50:32 2023

 

 

ARRIS

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All other trademarks are the property of their respective owners.

 

Hello Kevin

                    We understand that you are having slow speed issue, speed plan you are opted in by your internet service provider is a compatible speed plan but still you are facing slow speed issue is because of the cable signal level issue. There are some important things that should be within a specific range in order for the internet to work properly. First, the SNR should be above 33 on all of them. The downstream power should always be between -15 and +15. The closer to 0 the better connection. Finally, your upstream power should always be between +45 and +51. On all of those values you should not have more than 3 decibels (or dB) between the lowest and the highest, By having the values in less than that, your device will have interrupted connection, slow or no connection at all.

                   Cable signal level will be different for every modem so may be the internet service provider sending signal level which is needed for their modems which is not matching with our Arris device so we would suggest you to try changing the cable signal level by contacting your internet service provider then monitor connection. 

 


I understand that the upstream power readings are slightly out of spec, but fail to see how that would prevent the modem from providing gig service. I’m getting a solid 560mbps from the modem, just as I was prior to the request to upgrade. If the upstream power was the issue, then wouldn’t I have been having problems with the 500mbps service? If upstream power was the issue, wouldn’t the modem at least been attempting to provide some varying speed between zero and a gig?  As it stands now, I have Cox blaming the modem, and Arris blaming Cox. I’m fairly confident here that Cox is the issue, but I need something more for ammunition than complaining to them about 10 dbmv of upstream power.