C3700 ipv4 speed 3x slower than ipv6 speed on comcast. Turning off WMM doesn't help.

[gdeglin]

I recently upgraded to a 150Mbps connection with Comcast.

After the upgrade, I see that my download speed is 50Mbps on ipv4, but 150Mbps on ipv6.

Searching online, I see that some users advise turning off WMM. However, after making this change, the speed falls to 25Mbps on both ipv4 and ipv6. 

Can someone please advise how to fix this? 

[gdeglin]

I accidentally uploaded the wrong second screenshot. Here is the right one...

[vkdelta]

Hi, your screenshots show pretty close speeds.

Do you have another screenshot to show the difference?

[gdeglin]

Please look again, you'll see that the first screenshot shows the following

ipv4: 52.32Mbps

ipv6: 139.04Mbps 

These results have been very consistent across multiple speed test sites and over several days.

Thanks.

[vkdelta]

for some reason those screenshots are showing. can you please post again?

Can you please PM me your MAC address and the location as well and the speedtest server you are trying?

also, what kind of laptop/NIC are you using?

what FW are you running and I assuming ISP is comcast.

this is kind of behaviour is very strange.

can you please try other port on the device as well?

[gdeglin]

Sorry about the images, here it is:

I've received these same results on my iPhone 6, a Late 2013 iMac running OS X Yosemite, that same iMac running Windows 7 through Boot Camp, and a Mid-2011 Macbook Air.

Firmware version V2.02.06 with Comcast. 

This issue only happens on Wireless. Switching to a direct ethernet connection resolves the problem.

PMing you the additional details now.

[carl321]

PROBLEM SOLVED !

As you may have seen ive been having alot of issues with this device. The solution is DONT BUY this device if you are with COMCAST !. Here is why:

1. Slow speeds on wifi were due to an out dated firware version on the device according to NETGEAR (Tier 3 agent at the HQ in California) 

2. After a FCC complaint that I filed; someone from Corp office at COMCAST called me. HE checked with his senior engineers and said that COMCAST does not have the latest firmware for the netgear device. He accepted that the firmware is completely handled (updated) by COMCAST and not NETGEAR (for the first time)

3. So basically dont use this device on COMCAST and if you want to but your own device in the future please check the compatible device which have been tested and passed with a 3 star rating at COMCAST website. link : http://mydeviceinfo.comcast.net

Make:		Netgear
Model:		C3700-100NAS (Retail)
Retail:		Yes
Device Type:		Gateway
DOCSIS Version:		3.0
End of Life?		No
Certification:

 certification should have 3 stars according to COMCAST for that device to have the latest firmware on it !

If you look carefully on this list Netgear device is not properly tested at COMCAST and they will not be doing anything in the near future. However Motorola / ARRIS devices are fuly supported by COMCAST (becasuse they own 10-15% of ARRIS 😄 ) 

Sadly ARRIS devices arent the best and their wifi signal strength is absurb compared to some other providers. 

---------

I bought a Airport express router for $85 on amazon and this has fixed all my wifi issues. (thank you Apple)

Basically im using a $150 device as just a dumb modem 😞

Only if I knew about this corporate mumbo jumbo earlier. God Bless America !

[manneherrmann]

Hi,

I have the same problem/ made the same mistake. However, several comcast techs as well as a tech supervisor tried to resolve an issue with the speed and no one pointed out that the netgear firmware might be the problem. If they would have, I could have still returned/ exchanged the router to Bestbuy. Now I'm stuck with it and no one takes responsibility.

Would you be so kind and forward the complaint that you filed with the FCC? I consider doing the same as well as a complaint with the BBB.

[munnlete]

What did any of you commenters in this thread buy instead?  I am having a similar problem with the c3700 and comcast.

[gdeglin]

So I decided to look into this again before spending money on a new router. I tried disabling WMM support again to see if that resolved the issue (it actually slowed things down the last time I tried). Well for whatever reason it worked this time!

I tried enabling/disabling WMM several times and running a speed test each time. Every time I tried with WMM enabled, IPV4 speeds were between 50 and 55Mbps. With it off they were consistently over 150Mbps.

Overall I would still recommend against buying the C3700/N600. On top of this issue, the first one I bought was verifiably defective so overall I've lost a lot of time getting something working that should have been fine out of the box.

Screenshot of speed test after disabling WMM on Comcast:

[Big_A_NJ]

I have the same exact problem as you described, but I'm stuck with the disable/re-enable WMF to no avail no matter how many times I try. I still either get 25/25 Mbps with WMF disabled or 50/125 with it disabled. Can you think of any other changes you might have made that would result in fast speeds for both IP4 and IP6? Thanks!

[RedNinja]

I believe people are talking about WMM instead of WPF, but anyways, that did not help my cause.