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Re: 31 of 32 Downstream Bonded Channels

dude1
New Poster

Re: 31 of 32 Downstream Bonded Channels

I am experiencing a similar issue, only getting 31 of 32 locked channels with a Netgear CM1100 modem and unable to sustain speeds more than about 900 mbps.   I have also enabled link aggregation on the WAN ports to my router hoping it would allow me to get the full bandwidth, but that has not helped.

Could the lack of all 32 channels locking be the issue?  It would be great if a knowledgeable Comcast tech could reply!

EG
Expert

Re: 31 of 32 Downstream Bonded Channels

Be advised that many, if not most local systems have dropped back from using 32 downstream channels to using 31 since the DOCSIS 3.1 / OFDM channel for the gigabit speed tier was implemented. The gig speed tier is delivered via that channel, not the QAM256 channels.

 

Is there a downstream channel labeled as *OFDM / PLC* or as *Other* being shown ?

 

Please post the *Downstream Power Level*, the *Upstream Power Level*, and the *SNR* (Signal to Noise Ratio) numbers. 

 

Also post the error log entries in their entirety.




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dude1
New Poster

Re: 31 of 32 Downstream Bonded Channels

Hi, thanks for your assistance.  Here is what the cable connection screen on the CM1100 cable modem is showing:

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 Channel567000000 HzLocked
Connectivity StateOKOperational
Boot StateOKOperational
SecurityEnableBPI+
IP Provisioning ModeHonor MDDIPv6 only

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

ChannelLock StatusModulationChannel IDFrequencyPowerSNR / MERUnerrored CodewordsCorrectable CodewordsUncorrectable Codewords
1LockedQAM25629567000000 Hz2.4 dBmV40.5 dB190736596418630
2LockedQAM2561375000000 Hz2.3 dBmV42.3 dB19062392691430
3LockedQAM2562381000000 Hz2.6 dBmV42.3 dB19062445151750
4LockedQAM2563387000000 Hz2.2 dBmV42.4 dB19062460021800
5LockedQAM2564393000000 Hz2.1 dBmV42.2 dB19062498751790
6LockedQAM2565399000000 Hz1.8 dBmV42.4 dB19062547021970
7LockedQAM2566405000000 Hz1.7 dBmV42.3 dB19062600962350
8LockedQAM2567411000000 Hz1.7 dBmV42.2 dB19062627482620
9LockedQAM2568417000000 Hz1.9 dBmV42.2 dB19062776642410
10LockedQAM2569423000000 Hz2.0 dBmV42.1 dB19062835892530
11LockedQAM25610435000000 Hz2.6 dBmV42.3 dB19062891172520
12LockedQAM25611441000000 Hz2.8 dBmV42.2 dB19062904763680
13LockedQAM25612447000000 Hz3.0 dBmV42.4 dB19062931003240
14LockedQAM25613453000000 Hz3.2 dBmV42.3 dB19062976703570
15LockedQAM25614459000000 Hz3.3 dBmV42.3 dB19063017593810
16LockedQAM25615465000000 Hz3.2 dBmV42.1 dB19063032584640
17LockedQAM25616471000000 Hz2.8 dBmV42.1 dB19063556664570
18LockedQAM25617477000000 Hz2.9 dBmV42.3 dB19063601344680
19LockedQAM25618483000000 Hz2.4 dBmV42.1 dB19063643475360
20LockedQAM25619489000000 Hz2.4 dBmV42.1 dB19063676215750
21LockedQAM25620495000000 Hz2.4 dBmV41.7 dB19063704347490
22LockedQAM25621519000000 Hz3.0 dBmV39.2 dB190637427710190
23LockedQAM25622525000000 Hz3.0 dBmV41.9 dB19063794878230
24LockedQAM25623531000000 Hz2.8 dBmV41.9 dB190638291511640
25LockedQAM25624537000000 Hz2.8 dBmV41.6 dB190638658714070
26LockedQAM25625543000000 Hz2.7 dBmV41.8 dB190639001411710
27LockedQAM25626549000000 Hz2.3 dBmV41.5 dB190639409016860
28LockedQAM25627555000000 Hz2.5 dBmV41.6 dB190639729914890
29LockedQAM25628561000000 Hz2.6 dBmV41.6 dB190639943513900
30LockedQAM25630573000000 Hz2.3 dBmV41.5 dB190640094817340
31LockedQAM25631579000000 Hz2.0 dBmV41.3 dB190640004821990
32Not LockedUnknown00 Hz0.0 dBmV0.0 dB000

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

ChannelLock StatusModulationChannel IDFrequencyPower
1LockedATDMA917300000 Hz44.3 dBmV
2LockedATDMA1023700000 Hz43.5 dBmV
3LockedATDMA1130100000 Hz45.0 dBmV
4LockedATDMA1236500000 Hz43.8 dBmV
5Not LockedUnknown00 Hz0.0 dBmV
6Not LockedUnknown00 Hz0.0 dBmV
7Not LockedUnknown00 Hz0.0 dBmV
8Not LockedUnknown00 Hz0.0 dBmV

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

ChannelLock StatusModulation / Profile IDChannel IDFrequencyPowerSNR / MERActive Subcarrier Number RangeUnerrored CodewordsCorrectable CodewordsUncorrectable Codewords
1Locked0, 1, 2, 333690000000 Hz0.7 dBmV38.8 dB1108 ~ 2987317803165431276345140
2Not Locked000 Hz1.1 dBmV0.0 dB0 ~ 4095000

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

ChannelLock StatusModulation / Profile IDChannel IDFrequencyPower
1Not LockedUnknown00 Hz0 dBmV
2Not LockedUnknown00 Hz0 dBmV
EG
Expert

Re: 31 of 32 Downstream Bonded Channels

The stats are good. Be advised that around 940 (hardwired) is to be the max expected, so you are doing very well at 900.



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dude1
New Poster

Re: 31 of 32 Downstream Bonded Channels

Great, thanks!  My question is, can I use the wan aggregation feature of this modem to further increase the maximum by bonding the two gig connections on the modem?  I thought Comcast typically overprovisions the available bandwidth.  For example, when I had  a 100mbps plan, I was getting rates close to 150 - 200mbps.

I was hoping by using the WAN aggregation feature of this modem and the netgear r7800 router to which it is connected,  I could pull at or slightly higher than 1gbps. 

The comcast tech who came to the house seemed to be getting around 1.2 using his equipment.  He said he thought I may have been rate limited by the central office to no more than 1gbps, but if they are overprovisioning as they typically do, I thought by using wan aggregation, I could make use of this additional provisioned capacity. 

 

Thanks for all your help!

EG
Expert

Re: 31 of 32 Downstream Bonded Channels

Give it a try. I've seen posts here indicating that some people do indeed get around 1.2 Gbps that way. Good luck !



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