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slow download speed Netgear C7800

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slow download speed Netgear C7800

Currently on a 300Mbps plan but getting around 30Mbps as of late with my Netgear C7800. I've had the modem for a year without issue but I'm leaning towards it being the issue as I switched back to an older modem and was getting 200+ Mbps. Wanted a 2nd opinion before I replace my modem/router. Channels below:

ewolff96_0-1604962253611.png

Uploads seem fine. I measured the downloads a few times across the week and did the usual reboot, unplug, reset troubleshooting already.

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Re: slow download speed Netgear C7800

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Re: slow download speed Netgear C7800

 
ChannelLock StatusModulationChannel IDFrequencyPowerSNRCorrectablesUncorrectabables
1LockedQAM25637675000000 Hz1.4 dBmV40.3 dB00
2LockedQAM2569507000000 Hz1.6 dBmV41.0 dB00
3LockedQAM25610513000000 Hz1.6 dBmV41.2 dB00
4LockedQAM25611519000000 Hz1.4 dBmV41.1 dB00
5LockedQAM25612525000000 Hz1.3 dBmV41.0 dB00
6LockedQAM25613531000000 Hz1.3 dBmV41.1 dB00
7LockedQAM25614537000000 Hz1.2 dBmV41.2 dB00
8LockedQAM25615543000000 Hz1.0 dBmV40.9 dB00
9LockedQAM25616549000000 Hz0.7 dBmV40.5 dB10
10LockedQAM25617555000000 Hz1.0 dBmV40.9 dB00
11LockedQAM25618561000000 Hz1.2 dBmV40.8 dB00
12LockedQAM25619567000000 Hz1.3 dBmV40.8 dB00
13LockedQAM25620573000000 Hz1.4 dBmV40.8 dB00
14LockedQAM25621579000000 Hz1.6 dBmV40.9 dB00
15LockedQAM25622585000000 Hz1.7 dBmV40.9 dB00
16LockedQAM25623591000000 Hz1.6 dBmV40.9 dB00
17LockedQAM25624597000000 Hz1.2 dBmV40.7 dB00
18LockedQAM25625603000000 Hz1.2 dBmV40.7 dB00
19LockedQAM25626609000000 Hz0.9 dBmV40.5 dB00
20LockedQAM25627615000000 Hz0.9 dBmV40.5 dB00
21LockedQAM25628621000000 Hz1.1 dBmV40.3 dB1715800954519
22LockedQAM25629627000000 Hz1.4 dBmV40.6 dB16998031760392
23LockedQAM25630633000000 Hz1.7 dBmV32.6 dB1191400322229600
24LockedUnknown31639000000 Hz1.6 dBmV0.0 dB00
25LockedQAM25632645000000 Hz1.6 dBmV40.6 dB00
26LockedQAM25633651000000 Hz1.8 dBmV40.6 dB00
27LockedQAM25634657000000 Hz1.1 dBmV40.2 dB00
28LockedQAM25635663000000 Hz1.2 dBmV40.3 dB00
29LockedQAM25636669000000 Hz1.2 dBmV40.5 dB00
30LockedQAM25638681000000 Hz1.7 dBmV40.3 dB00
31LockedQAM25639687000000 Hz1.6 dBmV40.4 dB00
32Not LockedUnknown00 Hz0.0 dBmV0.0 dB00
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Expert

Re: slow download speed Netgear C7800

There is a problem here;

 

21LockedQAM25628621000000 Hz1.1 dBmV40.3 dB1715800954519
22LockedQAM25629627000000 Hz1.4 dBmV40.6 dB16998031760392
23LockedQAM25630633000000 Hz1.7 dBmV32.6 dB1191400322229600
24LockedUnknown31639000000 Hz1.6 dBmV0.0 dB0

0

 

There are a large number of uncorrected bit errors on these channels and the SNR is too low / out of spec on channel 23. And channel 24 isn't even locked in. Perhaps there is noise ingress at those frequencies into the line(s) somewhere.

 

That can cause random disconnects, spontaneous re-booting of the modem, speed, packet loss, latency problems, and the un-bonding of channels. Some stuff tha you can try but you may need a tech out to investigate / correct this.

In a self troubleshooting effort to try to obtain better connectivity / more wiggle room, check to see if there are there any excess/unneeded coax cable splitters in the line leading to the modem that can be eliminated/re-configured. Any splitters that remain should be high quality and cable rated for 5-1002 MHz, bi-directional, and no gold colored garbage types like GE, RadioShack, RCA, Philips, Leviton, Magnavox, and Rocketfish from big box stores like Home Depot, Lowes, Target, Wal-Mart etc. Splitters should be swapped with known to be good / new ones to test

If there aren't any unneeded splitters that can be eliminated and if your coax wiring setup can't be reconfigured so that there is a single two way splitter connected directly off of the drop from the street/pole with one port feeding the modem and the other port feeding the rest of the house/equipment with additional splits as needed, and you've checked all the wiring and fittings for integrity and tightness and refresh them by taking them apart then check for and clean off any corrosion / oxidation on the center wire and put them back together again, then perhaps it's best to book a tech visit to investigate and correct.

 



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