Rookie

Arris SB6141 -- T3/T4/MDD Timeouts -- Incompatible w/ speed?

I own the Arris SB6141. When I activated my service in 9/2017, I occasionally had T3/T4 timeouts -- always late hrs after midnight -- where the modem wouldn't connect to the net for periods at a time. Then, it miraculously stopped for months, until 2 days ago when I had it again -- this time it gave a "MDD" timeout.

 

What I'm trying to figure out is if this issue is from the modem (or modem incompatibility*) OR issues w/ wiring coming into my apt. I'm in an apt building in New York. *I ask this because although I pay for 60mbps, Spectrum recently bumped my speed to 200+ mbps. According to this page, is the SB6141 unsuitable for this speed? Spectrum lists it under 100mbps, but then why does Arris rate it for "up to 343mbps?"

 

Thanks for any insight. Please let me know if I should post any logs.

6 REPLIES
Helper

Re: Arris SB6141 -- T3/T4/MDD Timeouts -- Incompatible w/ speed?

What a modem is technically able to achieve and what an ISP is willing to provision are two different things. While the 6141 can technically achieve higher speeds under perfect lab conditions, Spectrum knows that perfect lab conditions do not exist in the real world. 

 

The T3/T4 errors are caused by physical coax problems. Can you post the modem's signal levels to see if something jumps out at us?

Rookie

Re: Arris SB6141 -- T3/T4/MDD Timeouts -- Incompatible w/ speed?

Thanks for the reply, posting signal + log from most recent reset from where it started working again. Note this most recent time, the "MDD" was the trigger; the T3/4's might be from me unplugging the coax etc. to try to get it to work.

Downstream Bonding Channel Value
Channel ID24 22 23 21 
Frequency417000000 Hz 405000000 Hz 411000000 Hz 399000000 Hz 279000000 Hz 285000000 Hz 291000000 Hz 297000000 Hz 
Signal to Noise Ratio39 dB 38 dB 39 dB 38 dB 38 dB 39 dB 39 dB 39 dB 
Downstream ModulationQAM256 QAM256 QAM256 QAM256 QAM256 QAM256 QAM256 QAM256 
Power Level
 
7 dBmV  6 dBmV  6 dBmV  7 dBmV  7 dBmV  7 dBmV  7 dBmV  7 dBmV  

 

Upstream Bonding Channel Value
Channel ID
Frequency24200000 Hz 37000000 Hz 30600000 Hz 19400000 Hz 
Ranging Service ID624 624 624 624 
Symbol Rate5.120 Msym/sec 5.120 Msym/sec 5.120 Msym/sec 2.560 Msym/sec 
Power Level40 dBmV 40 dBmV 40 dBmV 40 dBmV 
Upstream Modulation[3] QPSK
[1] 16QAM
[2] 64QAM
 
[3] QPSK
[1] 16QAM
[2] 64QAM
 
[3] QPSK
[1] 16QAM
[2] 64QAM
 
[3] QPSK
[2] 16QAM
 
Ranging StatusSuccess Success Success Success 

 

Signal Stats (Codewords) Bonding Channel Value
Channel ID24 22 23 21 
Total Unerrored Codewords5994403358 5994423021 5994414483 5994431205 5994399297 5994398860 5994401070 5994398706 
Total Correctable Codewords74 24 28 27 11 52 26 15 
Total Uncorrectable Codewords664 575 476 578 685 622 656 619 

 

Time Priority Code Message

May 17 2018 00:44:336-NoticeI401.0TLV-11 - unrecognized OID
May 17 2018 00:44:335-WarningZ00.0MIMO Event MIMO: Stored MIMO=-1 post cfg file
May 17 2018 00:44:203-CriticalR02.0No Ranging Response received - T3 time-out
May 17 2018 00:43:186-NoticeI401.0TLV-11 - unrecognized OID
May 17 2018 00:43:185-WarningZ00.0MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1
Jan 01 1970 00:06:553-CriticalR02.0No Ranging Response received - T3 time-out
Jan 01 1970 00:06:105-WarningT203.0MDD message timeout
Jan 01 1970 00:00:166-NoticeN/ACable Modem Reboot from GUI/Configuration page
Jan 01 1970 00:10:005-WarningT203.0MDD message timeout
Jan 01 1970 00:00:166-NoticeN/ACable Modem Reboot due to power reset
Proven Sharer

Re: Arris SB6141 -- T3/T4/MDD Timeouts -- Incompatible w/ speed?

The MDD error message was the result of you powering off the modem.  It is probably not the  cause of anything service affecting, just telling its part of the total story written in the status log.  As you can see, the power reset erased all previous historical events from the log.  

Rookie

Re: Arris SB6141 -- T3/T4/MDD Timeouts -- Incompatible w/ speed?

Right when it started to drop the connection again, I went to the log & it was showing ONLY MDD errors. From what you're seeing in this log now, you're correct -- I did a hard reset to get it to work & it cleared the log. But when this issue returned, the log was only showing MDD errors.  Is there anything telling from the signals?

 

Thank you.

Proven Sharer

Re: Arris SB6141 -- T3/T4/MDD Timeouts -- Incompatible w/ speed?

Since powering the modem off erases the previous history, we won't know until you post all of the error messages here.   MDD error messages aren't the same as T3 or T4 timeout warnings. 

 

And for those following along, this customer is located in the NYC area, which has a history of both ingress interference on several specific DS channels and generic system maintenance deficiencies, plus a large number of apartment buildings on private contracts carried over from the previous franchise holders. 

Rookie

Re: Arris SB6141 -- T3/T4/MDD Timeouts -- Incompatible w/ speed?

Thanks. That's the extent of the logs now. Since it's so intermittent (6 mo. since it's happened), I have no idea when it'll happen again. It was happening quite often after initial activation last yr, which lends suspicion to maintenance issues.

 

If anyone can ultimately recommend switching to the next-tier modem (Arris SB6183) for more DS channels, I'm interested if it's the solution, even though the SB6141 is drawing in 200mbps+ right now.