2

This is a cross post from superuser.com since no one over there seems to know anything.

I recently replaced a dying D-Link router (DI-524) with a Cisco/Linksys RSV4000. I'm really happy with the device but it seems when my cable modem is plugged in to it I lose 1/3 of my download speed. When I plug the modem right into my desktop I get 30mb/s down and 5mb/s up, but going through the router I get 20mb/s down.

I had a problem like this at work when we switched to Comcast as their boost service didn't work with the http proxy on our Watchguard firewall. So I tried turning off every option in the router to see if that had an effect but that didn’t change anything. I never had this problem with the old D-Link.

Someone said to check my MTU and change it to 1400 from 1500 but that didn't do anything on either the router or the desktops.

Community
  • 1
Brian Surowiec
  • 299

2 Answers2

5

http://www.dslreports.com/forum/r18508174-RVS4000-Speed-problems-explained

Disabling IPS might work.

David
  • 246
2

Changing MTU on a router connected to an ISP can cause more problems than it fixes, but 1500 is a pretty standard number.

Other issues can be QoS. If your router has built in QoS it may be deliberately throttling your HTTP connections, although if there's nothing else happening on the router then this should not be the case.

The other issue may be that 30Mbps is a fairly high link speed, so it may be possible that the Linksys's processor can't keep up with it. I've also seen routers that only have a 10mb router uplink port which screws you over when you sync at > 10Mb.

The 30Mb speed - where are you getting that from? Actual throughput (i.e. running a speed test in a browser), or looking at the sync speed in the router? If you're getting it through a speedtest site, check to see on the router if it's syncing at a similar speed, or if it claims to be syncing at 30Mb but you're only getting 20Mb.

Mark Henderson
  • 69,480