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Another CBR750 and Comcast/Xfiniity ISP Service Issue
Hi, I'm creating this post in response to https://community.netgear.com/t5/Orbi-with-Built-in-Cable-Modem/NOTICE-CBR750-and-Comcast-Xfiniity-ISP-Service-Issue/m-p/2286189 I have a CBR750 with...
I have 2 RBS satellites. The CBR is on the ground level, one satellite is upstairs and the other is down in the basement. Home is around 3400 sq ft over 3 levels.
Just curious, how does the WiFi channel impact the WAN performance? It is currently set to auto, but I have previously set this to a manual setting trying to minimize the interference. It didn't resolve the instability on the WAN side. Naturally there are multiple WiFi networks around, but my power levels stand out substantially above neighbors. Armor is currently enabled based on the replacement of the router but it will expire in a day - I don't have an issue manually disabling it as I don't intend paying for it going forward. There's no separate ISP Modem since the CBR750 is a modem/router combo device.
I will perform the factory reset and other suggested configs over this weekend as I can't afford the downtime while working from home.
I initially subscribed for 800Mb/s speed from Xfinity. On their app, I see two different values. In one place I see 800Mb/s and in another I see 1000Mb/s. The modem syncs at just under 1200Mb/s download and around 17Mb/s upload.
Ok. Just know that last year CC/XF was said to stop support of 1Gb plan and split into 800Mpbs and 1.2Gb. Found that others with the CBR had issues when the ISP upgraded them to 1.2Gb. NG has been working with the ISP since last year on this. Technically the CBR modem side can handle the 1.2Gb input, but the LAN side won't due to the 1000Mpbs LAN ports. Been recommended if users get 1.2Gb, downgrade to 800Mpbs for the CBR.
After your factory reset and setup from scratch this weekend please repost both cable connections and event log pages.
I have passed your post thread on to NG for review.
I factory reset and applied all suggested configurations yesterday evening. A few observations from my side:
1. After the factory reset the modem sychronized at 800 Mb/s
2. As I was configuring LAN and other options the modem had to reboot a few times. It subsequently synchronized at 1000Mb/s and eventually at 1200Mb/s
3. I experienced an issue with some of my devices not obtaining DHCP leases after reboot. I had to restart the modem 3 times until it eventually responded to DHCP requests from all of my devices connected to the network. Both 2.4GHz as well as 5GH devices were affected by this.
I have an appointment with Xfinity today - I hope to get the speed set back to 800 Mb/s. Needs to run for a few days before I can declare it is stable.
Current cable diagnostics:
Cable Diagnostic Status: Good Action: Your setup looks fine. If you are still experience an internet issue, the Netgear Cable Knowledge Base can provide additional troubleshooting info. Internet Access: Green Downstream Status: Green Upstream Status: Green Refresh Save Cable Diagnostic Info Advanced Information Frequency Start Value This field below allows you to modify the frequency the cable modem start with its scan during initialization and registration. Enter the new start frequency and restart the cable modem for it to take effect. Starting Frequency Startup Procedure Procedure Status Comment Acquire Downstream Channel 471000000 Hz Locked Connectivity State Ok Operational Boot State Ok Operational Security Enabled BPI+ IP Provisioning Mode Honor MDD honorMdd(4) Downstream Bonded Channels Channel Lock Status Modulation Channel ID Frequency Power SNR Correctables Uncorrectable 1 Locked QAM 256 1 453000000 Hz 0.0 dBmV 43.3 dB 11 0 2 Locked QAM 256 2 459000000 Hz 0.0 dBmV 40.9 dB 0 0 3 Locked QAM 256 3 465000000 Hz 0.0 dBmV 43.3 dB 0 0 4 Locked QAM 256 4 471000000 Hz 0.0 dBmV 43.3 dB 1 0 5 Locked QAM 256 5 477000000 Hz 0.0 dBmV 40.9 dB 0 0 6 Locked QAM 256 6 483000000 Hz 0.0 dBmV 40.9 dB 0 0 7 Locked QAM 256 7 489000000 Hz 0.0 dBmV 40.9 dB 0 0 8 Locked QAM 256 8 495000000 Hz 0.0 dBmV 40.9 dB 0 0 9 Locked QAM 256 9 501000000 Hz -0.2 dBmV 40.9 dB 0 0 10 Locked QAM 256 10 507000000 Hz 0.0 dBmV 40.9 dB 0 0 11 Locked QAM 256 11 513000000 Hz 0.0 dBmV 40.9 dB 7 0 12 Locked QAM 256 12 519000000 Hz 0.0 dBmV 40.3 dB 0 0 13 Locked QAM 256 13 525000000 Hz 0.2 dBmV 43.3 dB 0 0 14 Locked QAM 256 14 531000000 Hz 0.2 dBmV 40.9 dB 0 0 15 Locked QAM 256 15 537000000 Hz 0.2 dBmV 40.9 dB 0 0 16 Locked QAM 256 16 543000000 Hz 0.2 dBmV 40.9 dB 0 0 17 Locked QAM 256 17 549000000 Hz 0.5 dBmV 40.9 dB 0 0 18 Locked QAM 256 18 555000000 Hz 0.5 dBmV 43.3 dB 0 0 19 Locked QAM 256 19 561000000 Hz 0.7 dBmV 43.3 dB 0 0 20 Locked QAM 256 20 567000000 Hz 0.5 dBmV 40.9 dB 0 0 21 Locked QAM 256 21 573000000 Hz 0.7 dBmV 40.9 dB 0 0 22 Locked QAM 256 22 579000000 Hz 0.7 dBmV 40.9 dB 0 0 23 Locked QAM 256 23 585000000 Hz 0.7 dBmV 40.3 dB 0 0 24 Locked QAM 256 24 591000000 Hz 0.7 dBmV 40.9 dB 0 0 25 Locked QAM 256 25 597000000 Hz 0.7 dBmV 40.9 dB 0 0 26 Locked QAM 256 26 603000000 Hz 1.2 dBmV 40.9 dB 0 0 27 Locked QAM 256 27 609000000 Hz 1.5 dBmV 40.9 dB 0 0 28 Locked QAM 256 28 615000000 Hz 1.5 dBmV 40.9 dB 0 0 29 Locked QAM 256 29 621000000 Hz 1.2 dBmV 40.9 dB 0 0 30 Locked QAM 256 30 627000000 Hz 1.2 dBmV 40.3 dB 0 0 31 Locked QAM 256 31 633000000 Hz 1.2 dBmV 40.9 dB 0 0 32 Locked QAM 256 32 639000000 Hz 1.5 dBmV 40.9 dB 0 0 Upstream Bonded Channels Channel Lock Status US Channel Type Channel ID Symbol Rate Frequency Power 1 Locked ATDMA 4 5120 Ksym/sec 16400000 Hz 37.8 dBmV 2 Locked ATDMA 3 5120 Ksym/sec 22800000 Hz 38.5 dBmV 3 Locked ATDMA 2 5120 Ksym/sec 29200000 Hz 39.0 dBmV 4 Locked ATDMA 1 5120 Ksym/sec 35600000 Hz 39.8 dBmV 5 Not Locked N/A Unknown 0 Ksym/sec 0 Hz 0.0 dBmV 6 Not Locked N/A Unknown 0 Ksym/sec 0 Hz 0.0 dBmV 7 Not Locked N/A Unknown 0 Ksym/sec 0 Hz 0.0 dBmV 8 Not Locked N/A Unknown 0 Ksym/sec 0 Hz 0.0 dBmV Downstream OFDM Channels Channel Lock Status Modulation/Profile ID Channel ID Frequency Power SNR/MER Active Subcarrier
Number RangeUnerrored
CodewordsCorrectable
CodewordsUncorrectable
Codewords1 Locked 3 193 957000000 Hz -0.4 dBmV 42.5 dB 148~3947 0 0 0 2 Not Locked 0 0 0 Hz 0.0 dBmV 0.0 dB 0~4095 0 0 0 Upstream OFDMA Channels Channel Lock Status Modulation/Profile ID Channel ID Frequency Power 1 Not Locked 0 0 0 Hz 0.0 dBmV 2 Not Locked 0 0 0 Hz 0.0 dBmV Current System Time: Sun Jun 4 07:23:46 2023 System Up Time 12:42:23
