T3 T4 Timeouts and Cable Modem Registration - No Echo Version

[@exmerion]

I work as tech support for an ISP and our policy to send a tech out immediately if we see 3 or more T4 timeouts in a day. T3 timeouts have to be significant though.

[@Volpefirm]

Thanks for the input Exmerion. Good to hear you guys are in top of these.

[@exmerion]

@@Volpefirm Hey what do you think of the intel puma 7 chipsets? are they as bad as 6s?

[@Volpefirm]

Hi Exmerion, I try to stay agnostic between Intel and Broadcom, but this site does a pretty good job of stating the obvious: www.badmodems.com/Issue3.htm#:~:text=The%20Intel%20Puma%206%2F7,like%20high%20frequency%20stock%20trading.

[@DanielEkeroth]

wow - I wish my ISP worked the same. I get 20-30 T4 timeouts a day and they still insist on replacing modems (6th one of the same model now, Broadcom Fast 3890v3)

[@TravisTy2cMe]

@@Volpefirm Not Found The requested URL was not found on this server. Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.

[@gavinjf]

I found this video from your blog after googling like a madman trying to figure out what's wrong with my connection. I get T3 timeouts and T4 timeouts, and my connection is reset every few hours. I've had two Cox techs come out to look at it and they see nothing wrong with the signal on the line. I figured out I can reproduce the failure by just using lots of bandwidth - if I stream Netflix on my TV while watching youtube and streaming my screen with screen sharing software, the connection fails. It seems to be much more sensitive to me using upstream bandwidth. I managed to get my connection to fail within a minute in front of the last Cox tech who had just told me everything was "fine" lol. My question is - how should I troubleshoot this further? Is it the line in my house, or the one from the hub to my house, or the line to the hub from the pole? It's driving me crazy because I work from home and the internet is absolutely essential to do my job. My downstream signal power and SNR looks fine, but upstream channels are around 35-36 dBmV and when the T3/T4 timeouts cause my connection to reset, that upstream channel power drops to 23 dBmV on a few channels. I assume that's the modem resetting itself to the lowest levels when it can't get a ranging response (T3) or it gets no unicast maintenance opportunities (T4). My ears perked up when you said 23 was the lowest level as that's exactly what they reset to. My plan going forward is: run a coax cable out my window directly to the line coming from the street to check if it's a problem in my home's coaxial cables. If that fails then buy a new modem and try that. If that fails then I think Cox should run a new line from the hub to my house. If THAT fails, then I don't even know what to do. Any tips here? Thanks for the very informative video on docsis registration! edit: modem is an ARRIS SB8200. Is it possible for my cable operator to give me a different CMTS? I suspect over utilization since the T3 and T4 happen when I use a lot of upstream bandwidth, but I'm not very confident in my knowledge so far lol.

[@Volpefirm]

Let me know how your testing goes. 90% of issues are due to home wiring or due to the coax drop that you are referring to. So you may find the solution. :)

[@gavinjf]

Update for you: Had a 3rd cox tech come out. Same problems, we even tried bypassing my home's cabling and still had issues. Finally I just asked him to provision one of their rented modems to see if that's the issue. He installed a Technicolor CGM4331cox modem, which is an all in one (modem, router, wifi). Issue resolved immediately. Haven't had issues since even while streaming on multiple devices. It seems I had a bad modem, even though my SB8200 was brand new. I don't like renting their hardware though, and I'd like to use my edgerouter-x and ubiquiti wifi access point. For now, I'm just going to leave everything on their hardware to see if it lasts, fingers crossed! I'll try another new SB8200 later. I've read the 8200 can be more sensitive to line problems, so maybe that's it. For what it's worth, ARRIS specs say they expect upstream in the 40-50 dbMv range, and I always had ~35-36, and still do with Cox's modem.

[@Volpefirm]

Thanks for the update. Glad you got your issue resolved.

[@gavinjf]

Bought a new SB8200 and provisioned it. No problems so far with this either, so it seems I just got a lemon modem *shrug*. Thanks for the informative content nonetheless! I had no idea how coaxial internet worked before reading your blog and watching these videos :)

[@parkerbohnn]

The real answer is there's nothing you can do about it except move to another city.

[@Volpefirm]

The expensive but effective method.

[@parkerbohnn]

These two guys need to grow their hair.

[@Volpefirm]

Got any tips?

[@FunkyBananaBear]

The other guy's mic quality is horrific. Needs to be improved for educational purposes

[@Volpefirm]

Hi and thanks for watching. These are some of our older episodes and we did get John a new mic due to popular demand 👍

[@FunkyBananaBear]

@The Volpe Firm, Inc 😁 Thanks, much love guys!

[@FunkyBananaBear]

I just started getting into ya, so I couldn't tell haha

[@parkerbohnn]

I just rebooted my modem. I get 1 or more every minute not everyday. Before I used a broadband amplifier with active return I couldn't even hold an internet signal more than 20 minutes without it disconnecting. It has gotten worse as the years go by. DOCSIS Logs The DOCSIS event logs are shown here No. Time Type Priority Event 1 2022-04-19T06:36:30-0500 82000400 Critical Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=f8:1d:0f:87:5a:00;CMTS-MAC=00:17:10:9a:ef:8a;CM-QOS=1.1;CM-VER=3.1; 2 1970-01-01T00:02:09-0500 90000006 Notice CM Reboot Reason : POWER_OFF;CM-MAC=f8:1d:0f:87:5a:00;CMTS-MAC=00:17:10:9a:ef:8a;CM-QOS=1.1;CM-VER=3.1; 3 2022-04-19T11:54:36-0500 73040100 Notice TLV-11 - unrecognized OID;CM-MAC=f8:1d:0f:87:5a:00;CMTS-MAC=00:17:10:9a:ef:8a;CM-QOS=1.1;CM-VER=3.1; 4 2022-04-19T11:54:36-0500 68001102 Critical Config File Rejected due to Invalid or Unexpected TLV 11;CM-MAC=f8:1d:0f:87:5a:00;CMTS-MAC=00:17:10:9a:ef:8a;CM-QOS=1.1;CM-VER=3.1; 5 2022-04-19T06:55:17-0500 90000000 Warning MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=f8:1d:0f:87:5a:00;CMTS-MAC=00:17:10:9a:ef:8a;CM-QOS=1.1;CM-VER=3.1; 6 2022-04-19T06:55:18-0500 73040100 Notice TLV-11 - unrecognized OID;CM-MAC=f8:1d:0f:87:5a:00;CMTS-MAC=00:17:10:9a:ef:8a;CM-QOS=1.1;CM-VER=3.1; 7 2022-04-19T06:55:18-0500 68001102 Critical Config File Rejected due to Invalid or Unexpected TLV 11;CM-MAC=f8:1d:0f:87:5a:00;CMTS-MAC=00:17:10:9a:ef:8a;CM-QOS=1.1;CM-VER=3.1; 8 2022-04-19T06:55:22-0500 82001200 Warning RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=f8:1d:0f:87:5a:00;CMTS-MAC=00:17:10:9a:ef:8a;CM-QOS=1.1;CM-VER=3.1; 9 2022-04-19T06:55:23-0500 82000200 Critical No Ranging Response received - T3 time-out;CM-MAC=f8:1d:0f:87:5a:00;CMTS-MAC=00:17:10:9a:ef:8a;CM-QOS=1.1;CM-VER=3.1; 10 2022-04-19T06:55:26-0500 82001200 Warning RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=f8:1d:0f:87:5a:00;CMTS-MAC=00:17:10:9a:ef:8a;CM-QOS=1.1;CM-VER=3.1; 11 2022-04-19T06:55:28-0500 82000200 Critical No Ranging Response received - T3 time-out;CM-MAC=f8:1d:0f:87:5a:00;CMTS-MAC=00:17:10:9a:ef:8a;CM-QOS=1.1;CM-VER=3.1; 12 2022-04-19T06:56:00-0500 82001200 Warning RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=f8:1d:0f:87:5a:00;CMTS-MAC=00:17:10:9a:ef:8a;CM-QOS=1.1;CM-VER=3.1; 13 2022-04-19T06:56:07-0500 82000200 Critical No Ranging Response received - T3 time-out;CM-MAC=f8:1d:0f:87:5a:00;CMTS-MAC=00:17:10:9a:ef:8a;CM-QOS=1.1;CM-VER=3.1; 14 2022-04-19T06:56:18-0500 85010300 Warning Initializing Channel Timeout Expires - Time the CM can perform initial ranging on all upstream channels in the TCS has expired;CM-MAC=f8:1d:0f:87:5a:00;CMTS-MAC=00:17:10:9a:ef:8a;CM-QOS=1.1;CM-VER=3.1; 15 2022-04-19T06:56:18-0500 85010200 Warning TCS Partial Service;CM-MAC=f8:1d:0f:87:5a:00;CMTS-MAC=00:17:10:9a:ef:8a;CM-QOS=1.1;CM-VER=3.1; 16 2022-04-19T06:56:48-0500 82000400 Critical Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=f8:1d:0f:87:5a:00;CMTS-MAC=00:17:10:9a:ef:8a;CM-QOS=1.1;CM-VER=3.1; 17 2022-04-19T06:56:49-0500 74010100 Notice CM-STATUS message sent. Event Type Code: 6; Chan ID: 10; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=f8:1d:0f:87:5a:00;CMTS-MAC=00:17:10:9a:ef:8a;CM-QOS=1.1;CM-VER=3.1; 18 2022-04-19T06:57:18-0500 82000400 Critical Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=f8:1d:0f:87:5a:00;CMTS-MAC=00:17:10:9a:ef:8a;CM-QOS=1.1;CM-VER=3.1; 19 2022-04-19T07:00:03-0500 82000200 Critical No Ranging Response received - T3 time-out;CM-MAC=f8:1d:0f:87:5a:00;CMTS-MAC=00:17:10:9a:ef:8a;CM-QOS=1.1;CM-VER=3.1; 20 2022-04-19T07:00:18-0500 82000400 Critical Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=f8:1d:0f:87:5a:00;CMTS-MAC=00:17:10:9a:ef:8a;CM-QOS=1.1;CM-VER=3.1; Clear

[@Volpefirm]

Have you tried logging into your modems internal diagnostic page to check it's levels? You can google this and I think its in one of my videos too. This will show you modem's receive power level and transmit power level along with correctable and uncorrectable errors. You can then optimize your downstream and upstream amplification for your modem.

[@parkerbohnn]

@@Volpefirm WAN Up Time 001 days 04h:33m:04s With a 15/10 Motorola broadband amp Downstream Overview Port ID Frequency (Hz) Modulation Signal strength (dBmV) Channel ID Signal noise ratio (dB) Bytes Correcteds Uncorrectables 1 591000000 QAM256 3.099 7 37.355 3303653926 2 0 2 597000000 QAM256 3.400 8 37.636 1191522 1 0 3 603000000 QAM256 3.099 9 37.355 1999395 0 0 4 609000000 QAM256 3.000 10 37.355 1447689 1 0 5 849000000 QAM256 2.400 2 37.355 1000362 2 0 6 855000000 QAM256 2.400 3 37.636 1096105 0 0 7 861000000 QAM256 2.599 4 37.636 848396 0 0 8 579000000 QAM256 3.700 5 37.636 2001241 0 0 9 585000000 QAM256 3.700 6 37.636 2292848 0 0 10 279000000 QAM256 5.500 1 37.636 2388918 0 0 11 615000000 QAM256 3.400 11 37.355 1243995 0 0 12 621000000 QAM256 3.900 12 37.636 1314984 7 0 13 633000000 QAM256 4.099 13 37.355 573194 0 0 14 639000000 QAM256 4.400 14 37.355 544406 0 0 15 645000000 QAM256 4.699 15 37.636 771594 2 0 16 651000000 QAM256 4.900 16 37.636 562456 16 0 17 657000000 QAM256 4.400 17 37.636 301296 7 0 18 663000000 QAM256 4.400 18 37.355 716276 3 0 19 669000000 QAM256 4.500 19 37.355 829776 9 0 20 675000000 QAM256 4.599 20 37.636 1181578 2 0 21 681000000 QAM256 4.199 21 37.636 391261 8 0 22 687000000 QAM256 3.900 22 37.636 403399 0 0 23 693000000 QAM256 4.099 23 37.636 284996 0 0 24 699000000 QAM256 3.900 24 37.636 456498 1138 12922 25 705000000 QAM256 3.700 25 37.636 375440 2095 8993 26 711000000 QAM256 4.000 26 37.636 406469 0 0 27 717000000 QAM256 3.200 27 37.355 403567 0 0 28 723000000 QAM256 2.799 28 37.636 705971 1 0 29 825000000 QAM256 3.599 29 37.636 1610644 0 0 30 831000000 QAM256 3.000 30 37.636 1617644 9 0 31 837000000 QAM256 3.299 31 37.355 1693920 7 0 32 843000000 QAM256 3.299 32 37.636 1661296 4 0 Reset FEC Counters OFDM Downstream Overview Receiver FFT type Subcarr 0 Frequency(MHz) PLC locked NCP locked MDC1 locked PLC Location Occupied BW(MHz) Subcarriers PLC power(dBmv) 0 4K 275600000 YES YES YES 1544 283 ~ 472.95 3736 6.800003 1 4K 827600000 YES YES YES 1904 865 ~ 994.95 2551 3.299999 Upstream Overview Port ID Frequency (Hz) Modulation Signal strength (dBmV) Channel ID Bandwidth 1 38700000 64QAM 41.020 4 6400000 2 21100000 64QAM 39.260 1 3200000 3 32300000 64QAM 39.770 3 6400000 4 25900000 64QAM 40.020 2 6400000 OFDMA Overview Channel Index State lin Digital Att Digital Att BW (sc's*fft) Report Power Report Power1_6 FFT Size 0 RNG3 0.2281 3.8192 39.2000 52.1417 38.2500 2K 1 DISABLED 0.0000 0.0000 0.0000 0.0000 0.0000