Router seems to be restricting bandwidth from my cable modem

My Linksys E2000 router seems to be restricting the bandwidth of my Virgin SuperHub. I have been using http://speedtest.net for my results.

Connected directly, the SuperHub gives me an almost consistent speed of 100Mb/s but connected in "Modem Mode", using the E2000 as the router/DHCP server, gives me a maximum speed of around 30-50Mb/s. The router was wired with a 1GB/s Ethernet connection on all tests, and I have eliminated any other device.

I'm assuming there is some sort of bottleneck in the E2000 but it's meant to be a high-end consumer router so I'm not sure why.

What could potentially cause this bottleneck and are there settings I could use to improve the bandwidth performance?

Ryall

Posted 2012-07-25T16:17:28.633

Reputation: 502

Have you tried connecting your computer directly to the WAN port of the router and then inspecting the connection speed? Sometimes WAN specifications are different from LAN. – Chad Harrison – 2012-07-25T16:24:38.750

have you reset the firmware on the router? All of the ports are 10/100/1000 ports so there is no reason you should be getting a speed difference. – Ramhound – 2012-07-25T16:30:19.637

using the exact same cables? – Logman – 2012-07-25T16:30:51.850

@hydroparadise: No I haven't but I will try this – Ryall – 2012-07-25T16:30:56.970

@Ramhound: Yes, tried stock, DD-WRT and Tomato USB – Ryall – 2012-07-25T16:31:30.290

@Logman: Same cables every time – Ryall – 2012-07-25T16:31:45.173

@hydroparadise: Seems the WAN is 1Gb/s too - http://www.dd-wrt.com/wiki/index.php/Linksys_E2000

– Ryall – 2012-07-25T16:39:30.223

Answers

Most consumer wireless routers (by this I specifically mean home gateways with integrated 802.11 access point functionality) take a significant performance hit when doing NAT gatewaying instead of simply bridging between WAN and LAN/WLAN.

Leave your SuperHub in "modem mode", put your E2000 into bridge mode (NAT off), give your LAN-side wired Ethernet client your public IP address, and re-run your test. You'll probably see it keep up with 100mbps no problem.

By the way, the E2000 was never a high-end consumer router. It was just a $79 band-selectable 2x2:2 in late 2010. For comparison, the $179 Apple AirPort Extreme had been simultaneous dual-band 3x3:3 since late 2009. The E2000 was a mid-range device with a $70 price point, and that $70 probably didn't buy enough CPU to do NAT and still keep up with 100mbps or 1gbps wire speeds.

Spiff

Posted 2012-07-25T16:17:28.633

Reputation: 84 656

Thanks and good point. The AirPort Extreme seems to have a 1.2GHz CPU while the E2000 has a 354MHz CPU. Unfortunately, I need the NAT part of the router so I may have to just purchase a better one. Any recommendations (preferably DD-WRT and/or Tomato compatible)? – Ryall – 2012-07-26T09:41:58.860

Seems DD-WRT has something to do with it too: http://www.dd-wrt.com/phpBB2/viewtopic.php?p=538399

– Ryall – 2012-07-26T11:49:30.297

I ordered an Asus RT-N16 which has an extra 130MHz. The E2000 on 354MHz gets ~35Mbps on DD-WRT and ~85Mbps on Tomato. Hopefully this extra juice on the RT-N16 with Tomato will give me my full bandwidth and the features I need as well. Thanks for your answer, it helped me get to this point. – Ryall – 2012-07-26T11:56:09.243