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Cisco's avatar
Cisco
Dialled in
2 months ago

Internet drops out almost every day

Hi,

 

Since upgrading to the new GIG1 package, our broadband has been dropping offline randomly, mostly in the evenings. Sometimes it takes a good 10 minutes for it to come back online. This is becoming so often that we're becoming frustrated as a few of the important devices take some time to come back online.

 

This imapcts WiFi and hardwired devices.

 

The modem logs state the below when this happens:

28-08-2025 20:22:24

critical

Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=MAC1:HERE;CMTS-MAC=0MAC:2HERE;CM-QOS=1.1;CM-VER=3.1;

28-08-2025 20:22:24

critical

16 consecutive T3 timeouts while trying to range on upstream channel 8;CM-MAC=MAC1:HERE;CMTS-MAC=0MAC:2HERE;CM-QOS=1.1;CM-VER=3.1;

28-08-2025 20:21:16

critical

Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=MAC1:HERE;CMTS-MAC=0MAC:2HERE;CM-QOS=1.1;CM-VER=3.1;

Looks like there's some issues with the maintenance attempts. 

 

Can someone please look into this and ask the relevant team to resolve this issue?

 

Thanks,

29 Replies

    • Cisco's avatar
      Cisco
      Dialled in

      Thanks! I will check the figures again this evening. No faults in the area right now, but will check upon dropout. 

  • Client62's avatar
    Client62
    Alessandro Volta

    Share the stats from the Upstream and Downstream tabs,
    this is where signal level and quality issues can be seen.

    • Cisco's avatar
      Cisco
      Dialled in

      A massive amount of Pre/Post-RS errors, 2.67 billion! There's no visible issues with the new cable, no obvious RF interference, or things outside on the ingress to the house. Line has been fine for many years, until we received this new hub. Used all new parts provided in the package.

    • Cisco's avatar
      Cisco
      Dialled in

      Cannot paste tables, breaks HTML filtering of site. Here's it raw:

      SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=MAC1:HERE;CMTS-MAC=MAC2:HERE;CM-QOS=1.1;CM-VER=3.1;
      
      Downstream:
      
      Channel	Frequency (Hz)	Power (dBmV)	SNR (dB)	Modulation	Channel ID
      1	419000000	4.3	42	QAM 256	2
      2	427000000	3.3	41	QAM 256	3
      3	435000000	3.7	41	QAM 256	4
      4	443000000	4	42	QAM 256	5
      5	451000000	4.2	42	QAM 256	6
      6	459000000	4.3	42	QAM 256	7
      7	467000000	4.2	41	QAM 256	8
      8	475000000	4.1	42	QAM 256	9
      9	483000000	4.1	42	QAM 256	10
      10	491000000	4.4	42	QAM 256	11
      11	499000000	4.3	42	QAM 256	12
      12	507000000	4	41	QAM 256	13
      13	515000000	4.1	41	QAM 256	14
      14	523000000	4.4	42	QAM 256	15
      15	531000000	4.5	42	QAM 256	16
      16	539000000	4.3	42	QAM 256	17
      17	547000000	4.1	42	QAM 256	18
      18	555000000	4.4	42	QAM 256	19
      19	563000000	4.5	42	QAM 256	20
      20	571000000	4.2	42	QAM 256	21
      21	579000000	4	42	QAM 256	22
      22	587000000	4.3	42	QAM 256	23
      23	595000000	4.4	42	QAM 256	24
      24	603000000	4	41	QAM 256	25
      25	611000000	3.6	41	QAM 256	26
      26	619000000	3.7	41	QAM 256	27
      27	627000000	3.9	41	QAM 256	28
      28	635000000	3.6	41	QAM 256	29
      29	643000000	3.3	41	QAM 256	30
      30	651000000	3.4	41	QAM 256	31
      31	659000000	3.6	41	QAM 256	32
      
      3.0 Downstream channels
      
      Channel	Locked Status	RxMER (dB)	Pre RS Errors	Post RS Errors
      1	Locked	42	2529230	588741
      2	Locked	41	2476517	207621
      3	Locked	41	404219	180052
      4	Locked	42	339688	212228
      5	Locked	42	112907	106009
      6	Locked	42	707663	409589
      7	Locked	41	834652	433236
      8	Locked	42	1205026	367162
      9	Locked	42	991283	256143
      10	Locked	42	731573	105541
      11	Locked	42	468169	50673
      12	Locked	41	290988	29940
      13	Locked	41	174247	12478
      14	Locked	42	98693	16357
      15	Locked	42	44101	5535
      16	Locked	42	17605	1900
      17	Locked	42	6259	663
      18	Locked	42	3339	250
      19	Locked	42	2346	96
      20	Locked	42	1579	36
      21	Locked	42	1001	8
      22	Locked	42	542	0
      23	Locked	42	246	0
      24	Locked	41	86	0
      25	Locked	41	74	0
      26	Locked	41	42	0
      27	Locked	41	31	0
      28	Locked	41	31	0
      29	Locked	41	27	0
      30	Locked	41	28	0
      31	Locked	41	34	0
      
      3.1 Downstream channels
      
      Channel	Channel Width (MHz)	FFT Type	Number of Active Subcarriers	Modulation (Active Profile)	First Active Subcarrier (Hz)
      33	94	4K	1840	QAM 4096	1108
      
      3.1 Downstream channels
      
      Channel ID	Locked Status	RxMER Data (dB)	PLC Power (dBmV)	Corrected errors (Active Profile)	Uncorrectable errors (Active Profile)
      33	Locked	41	1.8	2673372372	2
      
      Upstream:
      
      Channel	Frequency (Hz)	Power (dBmV)	Symbol Rate (ksps)	Modulation	Channel ID
      0	49600000	48.8	5120	QAM 64	1
      1	43100000	48.8	5120	QAM 64	2
      2	36600000	48.3	5120	QAM 64	3
      3	30100000	47.8	5120	QAM 64	4
      4	23600000	48	5120	QAM 64	5
      
      3.0 Upstream channels
      
      Channel	Channel Type	T1 Timeouts	T2 Timeouts	T3 Timeouts	T4 Timeouts
      0	ATDMA	0	98	18	0
      1	ATDMA	0	98	18	0
      2	ATDMA	0	98	18	0
      3	ATDMA	0	98	18	0
      4	ATDMA	0	98	18	0
      
      3.1 Upstream channels
      
      Channel	Channel Width (MHz)	Power (dBmV)	FFT Type	Modulation
      6	10.4	43.5	2K	QAM 256
      
      3.1 Upstream channels
      
      Channel	Channel Type	Number of Active Subcarriers	First Active Subcarrier (Hz)	T3 Timeouts	T4 Timeouts
      6	OFDMA	208	74000000	0	0