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IThinkImMe's avatar
IThinkImMe
Aspirant
Jan 28, 2020

C7800 Dropping ISP connection

Been having a recurring issue with the connection to my ISP randomly dropping. Here are some of the facts:

ISP: Wave Broadband

Plan: 1GB/10mb

Router never loses power

Usually comes back within 60 seconds

In Cable Connections I randomly notice that only some of the downstream channels are active, sometimes 5-16 out of 32. And I never pick up a OFDMA upstream

Cable Information
 
Hardware VersionV1.07
 
Firmware VersionV3.01.36

 

Event Log

TimePriorityDescription
2020-01-27, 17:34:55.0Critical (3)Resetting the cable modem due to docsDevResetNow
Time Not EstablishedCritical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=bc:a5:11:7f:77:94;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2020-01-27, 17:52:23.0Critical (3)Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=bc:a5:11:7f:77:94;CMTS-MAC=00:17:10:8d:f6:a1;CM-QOS=1.1;CM-VER=3.1;
2020-01-27, 17:53:09.0Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=bc:a5:11:7f:77:94;CMTS-MAC=00:17:10:8d:f6:a1;CM-QOS=1.1;CM-VER=3.1;
2020-01-27, 17:53:09.0Critical (3)No Ranging Response received - T3 time-out;CM-MAC=bc:a5:11:7f:77:94;CMTS-MAC=00:17:10:8d:f6:a1;CM-QOS=1.1;CM-VER=3.1;
2020-01-27, 17:53:13.0Critical (3)Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=bc:a5:11:7f:77:94;CMTS-MAC=00:17:10:8d:f6:a1;CM-QOS=1.1;CM-VER=3.1;
2020-01-27, 17:53:19.0Critical (3)No Ranging Response received - T3 time-out;CM-MAC=bc:a5:11:7f:77:94;CMTS-MAC=00:17:10:8d:f6:a1;CM-QOS=1.1;CM-VER=3.1;
Time Not EstablishedCritical (3)SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=bc:a5:11:7f:77:94;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Time Not EstablishedNotice (6)Honoring MDD; IP provisioning mode = IPv4
Time Not EstablishedWarning (5)DHCP WARNING - Non-critical field invalid in response ;CM-MAC=bc:a5:11:7f:77:94;CMTS-MAC=00:17:10:8d:f6:a1;CM-QOS=1.1;CM-VER=3.1;
2020-01-27, 17:58:21.0Notice (6)

TLV-11 - unrecognized OID;CM-MAC=bc:a5:11:7f:77:94;CMTS-MAC=00:17:10:8d:f6:a1;CM-QOS=1.1;CM-VER=3.1;

 

<tabindex=-1>Startup Procedure</tabindex=-1>
ProcedureStatusComment
Acquire Downstream Channel675000000 HzLocked
Connectivity StateOKOperational
Boot StateOKOperational
SecurityENABLEDBPI+
IP Provisioning ModeHonor MDDIPv4 only
<tabindex=-1>Downstream Bonded Channels</tabindex=-1>
ChannelLock StatusModulationChannel IDFrequencyPowerSNRCorrectablesUncorrectabables
1LockedQAM25623675000000 Hz3.7 dBmV38.1 dB50
2LockedQAM2561543000000 Hz6.4 dBmV39.4 dB50
3LockedQAM2562549000000 Hz6.4 dBmV39.4 dB20
4LockedQAM2563555000000 Hz6.4 dBmV39.1 dB60
5LockedQAM2564561000000 Hz6.8 dBmV39.4 dB30
6LockedQAM2565567000000 Hz6.6 dBmV39.3 dB70
7LockedQAM2566573000000 Hz6.6 dBmV39.4 dB40
8LockedQAM2567579000000 Hz6.9 dBmV39.6 dB20
9LockedQAM2568585000000 Hz6.8 dBmV39.3 dB40
10LockedQAM2569591000000 Hz6.8 dBmV39.3 dB50
11LockedQAM25610597000000 Hz7.0 dBmV39.7 dB10
12LockedQAM25611603000000 Hz7.1 dBmV39.5 dB10
13LockedQAM25612609000000 Hz6.3 dBmV39.4 dB20
14LockedQAM25613615000000 Hz4.8 dBmV39.3 dB40
15LockedQAM25614621000000 Hz3.2 dBmV38.8 dB40
16LockedQAM25615627000000 Hz4.6 dBmV39.0 dB40
17LockedQAM25616633000000 Hz6.2 dBmV39.2 dB60
18LockedQAM25617639000000 Hz6.5 dBmV38.9 dB40
19LockedQAM25618645000000 Hz6.7 dBmV38.6 dB50
20LockedQAM25619651000000 Hz6.7 dBmV38.5 dB100
21LockedQAM25620657000000 Hz6.4 dBmV38.8 dB70
22LockedQAM25621663000000 Hz6.2 dBmV38.8 dB80
23LockedQAM25622669000000 Hz5.2 dBmV38.6 dB110
24LockedQAM25624681000000 Hz3.0 dBmV38.1 dB80
25LockedQAM25625687000000 Hz4.4 dBmV38.5 dB10
26LockedQAM25626693000000 Hz5.7 dBmV38.6 dB60
27LockedQAM25627699000000 Hz6.5 dBmV38.6 dB20
28LockedQAM25628705000000 Hz7.1 dBmV38.7 dB40
29LockedQAM25629711000000 Hz7.0 dBmV38.3 dB10
30LockedQAM25630717000000 Hz7.2 dBmV38.3 dB20
31LockedQAM25631723000000 Hz6.8 dBmV37.9 dB50
32LockedQAM25632729000000 Hz7.0 dBmV37.9 dB10
<tabindex=-1>Upstream Bonded Channels</tabindex=-1>
ChannelLock StatusUS Channel TypeChannel IDSymbol RateFrequencyPower
1LockedATDMA35120 Ksym/sec22400000 Hz42.5 dBmV
2LockedATDMA12560 Ksym/sec17600000 Hz41.0 dBmV
3LockedATDMA55120 Ksym/sec28800000 Hz43.8 dBmV
4LockedATDMA75120 Ksym/sec35200000 Hz43.8 dBmV
5Not LockedUnknown00 Ksym/sec0 Hz0 dBmV
6Not LockedUnknown00 Ksym/sec0 Hz0 dBmV
7Not LockedUnknown00 Ksym/sec0 Hz0 dBmV
8Not LockedUnknown00 Ksym/sec0 Hz0 dBmV
<tabindex=-1>Downstream OFDM Channels</tabindex=-1>
ChannelChannel IDIndicatorSubcarrier Zero FrequencyActive Subcarrier Number RangeTotal CodewordsUncorrectable Codewords
133Backup Primary347600000 Hz1108 ~ 2987196778860
20Other0 Hz0 ~ 000
<tabindex=-1>Upstream OFDMA Channels</tabindex=-1>
ChannelUpstreamIsMutedRanging StatusSubcarrier Zero FrequencyActive Subcarrier Number RangeSymbols Per FrameTx Power
1 Other0 Hz0 ~ 000 dBmV
2 Other0 Hz0 ~ 000 dBmV

6 Replies

  • IThinkImMe's avatar
    IThinkImMe
    Aspirant
    Jan 28, 2020

    Wave has sent 3 techs on site and they all say the line is good. They're putting the fault on the router.

    • FURRYe38's avatar
      FURRYe38
      Guru - Experienced User
      Jan 28, 2020

      Try a different modem/router, or try a modem only and external router. See if problem clears or pertists. Possible faulty C7800 as well and just needs replacing. 

      • IThinkImMe's avatar
        IThinkImMe
        Aspirant
        Jan 28, 2020

        Thanks for replying. I would like to state that I had another router previously that had the exact same symptoms as this one. Not sure of the exact model but it was an older Nighthawk. Support said I needed to update because it was DOCSIS 3.0 and my gig plan requires DOCSIS 3.1.