N600 C3700 Wifi Speeds Slow

[ezcashman1]

Does anyone know how to change the channel on the N600 C3700 modem? I'm getting 28mbps and I have Xfinity 150mbps internet I called Netgear and they wanted to charge me to walked me through it. That whole support process seemed a bit scammy to me. I mean I purchased your product and now that I upped my internet speed I have to pay you to get your product to do what it says on the side of the box. If anyone can help please do..Netgear is foul for this. They don't care enough about loyal customers to support them. We have to come in here and figure it out or pay them. SAD 

[TheEther]

Change the channel under basic wireless settings.  Directions are in the manual.

[rollie9999]

ISP supplying 300Mbs (verified) but router speedtests at 100Mbs back to ISP router. tried changing channels. rebooted router several times.  had ISP reboot router sever times. had ISP blow router out of their system and re-activate router as if new install.  reset router to factory defaults.  Nothing has worked. firmware is old (1.0 vs 2.0) and thought that might be the problem but ISP either can't or won't push the upgrade and Netgear will fix it only if I give them $137 for a 1 year service contract.  log message I get is:

2017-7-24, 14:24:26.0

Critical (3)

Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=c0:ff:d4:e2:32:b8;CMTS-MAC=00:17:10:94:1b:27;CM-QOS=1.1;CM-VER=3.0;

besides buying a new router, any suggestions??

[TheEther]

How did you verify that the ISP is supplying 300 Mbps?

Did you try a speedtest using a computer wired to the C3700?  There's no way the C3700 can deliver 300 Mbps over Wi-Fi.  The best you can get will be roughly 150 to 180 Mbps with a 5 GHz client.  It'll be roughly half of that with a 2.4 GHz client.

[rollie9999]

ISP's techs at my house and checked inside cable with their equipment. (wired 300+ Mbs ) connected their (make/model forgotten) dual band modem router to cable and wired to their laptop (313 Mbs). wireless connect to my laptop (265 Mbs @ 5 Ghz sitting 10 ft away from router).  reconnected Netgear C3700 to cable and tested with my laptop (wired: 105 Mbs, wireless 56 Mbs @ 5 Ghz sitting 10 ft away from router).  all speed tests conducted with ISP's web page (http://fish.tvcconnect.net) .  C3700 is rated for "up to" 300+ Mbs so expected much better than what I got.  On the verge of buying a new modem router because with all the grandkids here right now streaming is impossible.  Appreciate the help

[rollie9999]

thought something was wrong after my last post so I re-ran the speed test twice to  make sure this time.  something really wrong when the wired speed is 1/4 the wireless.  I'd attach the speed test print-outs but don't see that option

wired:  ~26 Mbs

wireless: ~105 Mbs (both 2.5 Ghz and 5Ghz)