Orbi WiFi 7 RBE973
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Re: C7800 Modem - Slow connections and Many Not Locked Channels

Andy_Royce
Aspirant

C7800 Modem - Slow connections and Many Not Locked Channels

Installed C7800 (Firmware V3.01.43) about three weeks ago to take advantage of Xfinity 1Gb service and reduce rental cost of Xfinity equipment.  Since C7800 has been installed internet speeds have been intermittent, inconsistent and slow at times.  Started watching downstream bonded channels going from locked to unlocked periodically sometimes very often and noted power levels were generally around -1.5 up to +3.0 and at times uncorrectables in the thousands.  Have had three Xfinity techs on site and finally got them to replace cables, cable ends, splitters, tighten all cable connection and replace the trasformer that supports a Xfinity 8 way splitter all of which helped to stableize power levels to =7.5-9.0 reduced uncorrectables to zero for now but did not help many of the downstream channels from going from locked to not locked and back again.   Tech verified power levels going into house at 13DbmV. Chart below is current status of the modem...lots of unlocked channels.  Xfinity tech said he was escalating issue to next tier to have them verify what is going on at head end.  I am not sure anything is wrong with the modem but after reading many other forum messages here I am not sure what to think as it appears I am not the only one to experience these issues.  Thoughts?

 

Frequency start Value
This field below allows you to modify the frequency the cable modem start with its scan during initialization and registration. Enter the new start frequency and restart the cable modem for it to take effect.
Starting Frequency

<tabindex=-1>Startup Procedure</tabindex=-1>

ProcedureStatusComment
Acquire Downstream Channel615000000 HzLocked
Connectivity StateOKOperational
Boot StateOKOperational
SecurityENABLEDBPI+
IP Provisioning ModeHonor MDDIPv6 only

<tabindex=-1>Downstream Bonded Channels</tabindex=-1>

ChannelLock StatusModulationChannel IDFrequencyPowerSNRCorrectablesUncorrectabables
1LockedQAM25625615000000 Hz8.0 dBmV39.9 dB00
2LockedQAM2561459000000 Hz9.5 dBmV40.5 dB00
3LockedQAM2562465000000 Hz9.6 dBmV40.2 dB00
4LockedQAM2563471000000 Hz9.1 dBmV40.3 dB00
5LockedQAM2564477000000 Hz8.7 dBmV40.0 dB00
6LockedQAM2565483000000 Hz8.8 dBmV40.3 dB00
7Not LockedUnknown00 Hz0.0 dBmV0.0 dB00
8Not LockedUnknown00 Hz0.0 dBmV0.0 dB00
9Not LockedUnknown00 Hz0.0 dBmV0.0 dB00
10Not LockedUnknown00 Hz0.0 dBmV0.0 dB00
11Not LockedUnknown00 Hz0.0 dBmV0.0 dB00
12Not LockedUnknown00 Hz0.0 dBmV0.0 dB00
13Not LockedUnknown00 Hz0.0 dBmV0.0 dB00
14Not LockedUnknown00 Hz0.0 dBmV0.0 dB00
15Not LockedUnknown00 Hz0.0 dBmV0.0 dB00
16Not LockedUnknown00 Hz0.0 dBmV0.0 dB00
17Not LockedUnknown00 Hz0.0 dBmV0.0 dB00
18Not LockedUnknown00 Hz0.0 dBmV0.0 dB00
19Not LockedUnknown00 Hz0.0 dBmV0.0 dB00
20Not LockedUnknown00 Hz0.0 dBmV0.0 dB00
21Not LockedUnknown00 Hz0.0 dBmV0.0 dB00
22Not LockedUnknown00 Hz0.0 dBmV0.0 dB00
23Not LockedUnknown00 Hz0.0 dBmV0.0 dB00
24Not LockedUnknown00 Hz0.0 dBmV0.0 dB00
25Not LockedUnknown00 Hz0.0 dBmV0.0 dB00
26Not LockedUnknown00 Hz0.0 dBmV0.0 dB00
27Not LockedUnknown00 Hz0.0 dBmV0.0 dB00
28Not LockedUnknown00 Hz0.0 dBmV0.0 dB00
29Not LockedUnknown00 Hz0.0 dBmV0.0 dB00
30Not LockedUnknown00 Hz0.0 dBmV0.0 dB00
31Not LockedUnknown00 Hz0.0 dBmV0.0 dB00
32Not LockedUnknown00 Hz0.0 dBmV0.0 dB00

<tabindex=-1>Upstream Bonded Channels</tabindex=-1>

ChannelLock StatusUS Channel TypeChannel IDSymbol RateFrequencyPower
1LockedATDMA15120 Ksym/sec30100000 Hz36.0 dBmV
2LockedATDMA25120 Ksym/sec36500000 Hz36.0 dBmV
3LockedATDMA35120 Ksym/sec17300000 Hz35.5 dBmV
4LockedATDMA45120 Ksym/sec23700000 Hz35.5 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
1159Non-Primary629600000 Hz1126 ~ 29692052570280
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

 

Model: C7800|Nighthawk X4S-AC3200 WiFi Cable Modem Router
Message 1 of 6

Re: C7800 Modem - Slow connections and Many Not Locked Channels

You might get better and quicker replies, and find other answers, over in the appropriate section for your device:

Cable Modems & Routers

No need to repost there, unless you want to – that will just clutter up the place with duplicated messages – but you might find advice related to your hardware.

I have asked the Netgear moderator to move your message.

Message 2 of 6
plemans
Guru

Re: C7800 Modem - Slow connections and Many Not Locked Channels

Try getting xfinity to repartition the C7800. I've had them send the wrong partitioning file to my modem before and cause issues. 

Message 3 of 6
Andy_Royce
Aspirant

Re: C7800 Modem - Slow connections and Many Not Locked Channels

Not sure what you mean by a "partitioning file...what is that?  I have not heard of that terminology before.

Message 4 of 6
antinode
Guru

Re: C7800 Modem - Slow connections and Many Not Locked Channels

> Not sure what you mean by a "partitioning file [...]

 

   My guess: "partition" --> "provision".

Message 5 of 6
plemans
Guru

Re: C7800 Modem - Slow connections and Many Not Locked Channels

@antinode you're right. Typing and not rereading again
Message 6 of 6
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