CM1200 and Xfinity connection issues

[Julia37]

I have new Modem for about a month. I registered modem with Xfinity successfully. I use a Google Wifi Router. 

I inconsistently have connection issues. DownStream is tyically blinking. 

Firmware is V3.02.01

attached is my event log - upstream shows Unlocked. 

I've had a Xfinity tech come out and said it was a port issue on outside of home. Worked ok for about 5 days. Today it is crashing every 10-15 mintues. Xfinity tech is coming out again this weekend 

Please give any guidance. 

[FURRYe38]

Have the ISP check the signal and line quality UP to the modem. Be sure the ISP provisions the modem correctly.
Be sure there are no coax cable line splitters in the between the modem and ISP service box. 
Be sure your using good quality RG6 coax cable up to the modem. 
Be sure to power OFF the modem for 1 minute them back ON.
https://community.netgear.com/t5/Cable-Modems-Routers/General-info-and-Troubleshooting-for-Cable-Mod...

[Julia37]

Xfinity tech came out and replaced ALL coax to my apartment. he did spot some shielding damage in some spots. 

However, still blinking downstream light. 

We did a hard reset on modem and hardwired directly to laptop. Still blinking downstream light. Here is recent Event log 

[FURRYe38]

Were all the Downstream channels locked in? I see 31 is locked in. 

What speed do you pay for UP and DOWN? 

Your only getting 1 channel on the UP BONDED locked in, there should be 4 I believe

Is LAG enabled on the modem? Link Aggregation

The ISP should look into this with you. Have them review the signal up to the modem and the event and cable connection logs. 

[Julia37]

i pay for Blast which is 200mps 

I cannot find where LAG shows on Netgear page. i attached more info from Admin Netgear Modem page 

[Julia37]

Disable
Enable (LACP-IEEE 802.3ad) (Port 1 & 2)

Ethernet Port Aggregation Status: Inactive

[FURRYe38]

Lag is here:

Ok the 16 channels would be only used I presume. What is your UP Load speeds? 

[Julia37]

Speed test 

234 mps down 

11 up 

I'm hard wired from modem to laptop / port 1 and downstream key still blinking 

Tech said I was getting 52 power at cable box outside my building, which is HIGH 

I'm getting 46 inside at modem 

[FURRYe38]

Might see if they can turn down the power to maybe 30's range? 

Heres miine is a ball park figure:

Downstream channels:

28 Locked QAM256 27 813000000 Hz -1.3 dBmV 37.4 dB 262 1164 29 Locked QAM256 28 819000000 Hz -1.7 dBmV 37.1 dB 242 1207 30 Locked QAM256 29 825000000 Hz -1.5 dBmV 37.3 dB 263 1192 31 Locked QAM256 32 843000000 Hz -1.7 dBmV 37.2 dB 264 1190 32 Not Locked Unknown 0 0 Hz 0.0 dBmV 0.0 dB 0 0

Upstream Bonded Channels

Channel Lock Status US Channel Type Channel ID Symbol Rate Frequency Power 1 Locked ATDMA 1 5120 Ksym/sec 36000000 Hz 39.5 dBmV 2 Locked ATDMA 2 5120 Ksym/sec 29000000 Hz 38.3 dBmV 3 Locked ATDMA 5 5120 Ksym/sec 22000000 Hz 38.8 dBmV 4 Locked ATDMA 6 2560 Ksym/sec 16000000 Hz 37.5 dBmV 5 Not Locked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV 6 Not Locked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV 7 Not Locked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV 8 Not Locked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV

So for 11 Mb up then only 1 channel maybe lock in for your ISP. I have 50Mbps on the UP and have 4 channels locked in. 

[Julia37]

I swapped power supplies to CM12oo modem and steady lights now and solid speed. 

I will observe next week and see if steady 

[FURRYe38]

Nice fine. Power supplies can go bad...

[Julia37]

Damn - within an hour. Down again w different power supply at modem. 

Xfinity coming out again tonight. Yesterdays tech said he was getting a power reading outside at cable box of 52 (too high) But 46 inside at modem. What is suitable power reading at box? Could this explain my issues and what should I ask tech to do today? 

thanks 

[Julia37]

Also I'm noticing that others on CM1200 are using older firmware. CM1200 v2.02.03 

I'm currently at 3.02.01

[FURRYe38]

I'd have them try to get the signal at the modem to under 40. Mines in the 30 range for me. Seems that the power is too high. Have them review the modems logs and connection status page. 

You can ask them if they can downgrade to v2 and see. Not sure if they will do that. Worth asking. 

[FURRYe38]

Ask them about attaching a attenuator to the back of the modem that connects to the coax cable line. Mines got one attached. Mines 6db

[Julia37]

I'm losing my mind.... Comcast tech back out yesterday and tech hard-wired his laptop to Netgear modem and no issues. Seems this might be a Google WiFi mesh (2nd gen) router and Netgear modem issue. attached are event logs, showing NO RANGING RESPONSE

No luck contacting Google wiFI tech support 

I've tried rebooting as suggestion in other Google / CM1200 threads in the exact steps with no luck 

any support is appreciated 

[FURRYe38]

Can you try a different router? Go to best buy or office max and find something fairly inexpensive and connect to the modem. Remove the Google router. See if something different causes the same problem or not. IF not, then the issue is with Google. 

[Julia37]

I factory reset my google wifi router. Not attemtping new cheap router. 

How does one install a older Netgear modem firmware version? Look at my critical event logs. I have version 3.02.01 

Comcast tech says they don't change firmware on their end. It's the modem side. Full report as attachment 

No Ranging Response received - T3 time-out;CM-MAC=08:36:c9:a4:3e:78;CMTS-MAC=00:01:5c:ac:d2:6a;CM-QOS=1.1;CM-VER=3.1

[FURRYe38]

The tech is incorrect. ISPs are in charge of all FW updates that gets pushed to cable modems. There is no user interface that allows users to push FW to there modems. Has to be done from the ISP side. 

[Julia37]

well after 5th Tech visit, Xfinity insists on swapping out modem for theirs. I will test for a month and see. I tried talking to internet support about this issue, but they all say ISP does not supply firmware. I'm so tired of this issue. 

Disappointed that Xfininty and Netgear cannot communicate on Firmware versions. 

Recent log activity 

Wed Mar 24 15:36:35 2021	Critical (3)	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:a4:3e:78;CMTS-MAC=00:01:5c:ac:d2:6a;CM-QOS=1.1;CM-VER=3.1;
Wed Mar 24 15:36:35 2021	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=08:36:c9:a4:3e:78;CMTS-MAC=00:01:5c:ac:d2:6a;CM-QOS=1.1;CM-VER=3.1;
Wed Mar 24 15:35:22 2021	Critical (3)	16 consecutive T3 timeouts while trying to range on upstream channel 1;CM-MAC=08:36:c9:a4:3e:78;CMTS-MAC=00:01:5c:ac:d2:6a;CM-QOS=1.1;CM-VER=3.1;
Wed Mar 24 15:35:22 2021	Critical (3)	Ranging Request Retries exhausted;CM-MAC=08:36:c9:a4:3e:78;CMTS-MAC=00:01:5c:ac:d2:6a;CM-QOS=1.1;CM-VER=3.1;
Wed Mar 24 15:35:22 2021	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=08:36:c9:a4:3e:78;CMTS-MAC=00:01:5c:ac:d2:6a;CM-QOS=1.1;CM-VER=3.1;
Wed Mar 24 15:34:40 2021	Critical (3)	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:a4:3e:78;CMTS-MAC=00:01:5c:ac:d2:6a;CM-QOS=1.1;CM-VER=3.1;
Wed Mar 24 15:34:40 2021	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=08:36:c9:a4:3e:78;CMTS-MAC=00:01:5c:ac:d2:6a;CM-QOS=1.1;CM-VER=3.1;
Wed Mar 24 15:33:09 2021	Critical (3)	16 consecutive T3 timeouts while trying to range on upstream channel 2;CM-MAC=08:36:c9:a4:3e:78;CMTS-MAC=00:01:5c:ac:d2:6a;CM-QOS=1.1;CM-VER=3.1;
Wed Mar 24 15:33:09 2021	Critical (3)	Ranging Request Retries exhausted;CM-MAC=08:36:c9:a4:3e:78;CMTS-MAC=00:01:5c:ac:d2:6a;CM-QOS=1.1;CM-VER=3.1;
Wed Mar 24 15:33:09 2021	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=08:36:c9:a4:3e:78;CMTS-MAC=00:01:5c:ac:d2:6a;CM-QOS=1.1;CM-VER=3.1;

[FURRYe38]

Some ISPs won't update user owned modems which is a shame. 

See how the ISP modem does. Let us know. 

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@Julia37 wrote:

well after 5th Tech visit, Xfinity insists on swapping out modem for theirs. I will test for a month and see. I tried talking to internet support about this issue, but they all say ISP does not supply firmware. I'm so tired of this issue. 

Disappointed that Xfininty and Netgear cannot communicate on Firmware versions. 

Recent log activity 

Wed Mar 24 15:36:35 2021	Critical (3)	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:a4:3e:78;CMTS-MAC=00:01:5c:ac:d2:6a;CM-QOS=1.1;CM-VER=3.1;
Wed Mar 24 15:36:35 2021	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=08:36:c9:a4:3e:78;CMTS-MAC=00:01:5c:ac:d2:6a;CM-QOS=1.1;CM-VER=3.1;
Wed Mar 24 15:35:22 2021	Critical (3)	16 consecutive T3 timeouts while trying to range on upstream channel 1;CM-MAC=08:36:c9:a4:3e:78;CMTS-MAC=00:01:5c:ac:d2:6a;CM-QOS=1.1;CM-VER=3.1;
Wed Mar 24 15:35:22 2021	Critical (3)	Ranging Request Retries exhausted;CM-MAC=08:36:c9:a4:3e:78;CMTS-MAC=00:01:5c:ac:d2:6a;CM-QOS=1.1;CM-VER=3.1;
Wed Mar 24 15:35:22 2021	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=08:36:c9:a4:3e:78;CMTS-MAC=00:01:5c:ac:d2:6a;CM-QOS=1.1;CM-VER=3.1;
Wed Mar 24 15:34:40 2021	Critical (3)	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=08:36:c9:a4:3e:78;CMTS-MAC=00:01:5c:ac:d2:6a;CM-QOS=1.1;CM-VER=3.1;
Wed Mar 24 15:34:40 2021	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=08:36:c9:a4:3e:78;CMTS-MAC=00:01:5c:ac:d2:6a;CM-QOS=1.1;CM-VER=3.1;
Wed Mar 24 15:33:09 2021	Critical (3)	16 consecutive T3 timeouts while trying to range on upstream channel 2;CM-MAC=08:36:c9:a4:3e:78;CMTS-MAC=00:01:5c:ac:d2:6a;CM-QOS=1.1;CM-VER=3.1;
Wed Mar 24 15:33:09 2021	Critical (3)	Ranging Request Retries exhausted;CM-MAC=08:36:c9:a4:3e:78;CMTS-MAC=00:01:5c:ac:d2:6a;CM-QOS=1.1;CM-VER=3.1;
Wed Mar 24 15:33:09 2021	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=08:36:c9:a4:3e:78;CMTS-MAC=00:01:5c:ac:d2:6a;CM-QOS=1.1;CM-VER=3.1;

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