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[richardnau]

Hi, everyone,

When my PC is directly connected to my cable modem (Motorola SB5100), I can download at between 19 and 20Mbps (Telstra Cable Extreme in Australia).

When I insert the DIR-655, I can't get past 8.7Mbps, irrespective of the setting of the WAN port speed in the GUI.

When I set for 10Mbps, I get downloads of 8.7Mbps.

When I set for 100Mbps, I get downloads of 8.7Mbps.

When I set for 1000Mbps, I can't connect to the cable modem (not surprising - the cable modem only supports 10Mbps or 100Mbps).

When I set for AUTO, I get downloads of 8.7Mbps.

I SUSPECT that the DIR-655 is negotiating to talk to the cable modem at only 10Mbps, even when set for 100Mbps. But I can't confirm this as the cable modem has no way to determine what speed the link is operating at (no LEDs and nothing in its GUI), and the DIR-655 similarly gives me no information (no link speed LEDs, nothing I can find in the GUI).

Questions:

1) Has anybody else experienced a similar problem? How did you fix it?

2) Does anybody know how I can confirm that the ethernet link between the router and cable modem is operating at 100Mbps?

3) Can anyone think of a reason why the router might otherwise be throttling traffic?

(All wired LAN ports operating at 1Gbps, confirmed by the PCs. SPI enabled. QoS disabled. Apart from apparent speed throttling, router operating perfectly.)

[Fatman]

If you lock down an interface on any Ethernet device down to a particular speed then it will not, for any reason, operate at other than that speed.  This is why locking down your DIR-655 to 1000 Mbps does not result in 100 Mbps traffic.

[richardnau]

Fatman,

Thanks!

So, why would my throughput with router in circuit be so low? I know that this router has plenty of horsepower and can easily manage 20Mbps WAN-LAN speed... Suggestions appreciated.

[jupiter]

If richardnau is running a on a cable modem, the MTU should be 1500

My DIR-655 at my home is connected to a DCM-202 with COX internet.

My connection is rated at 15,000KB/s
I get somewhere around 14,500 from http://speakeasy.net/speedtest using the los angeles server.  if i connect to the New York server.  my connection drops to 7,000 KB/s

richardnau  what are you using to measure your WAN speed?

[richardnau]

I use the this speed test: http://www.speedtest.net/

If I connect PC directly to cable modem and use Sydney server, I get 19 - 20Mbps.

If I connect via router (everything else unchanged) I get 8.7Mbps.

R.

[PsyOpWarlord]

I get good speeds on mine thru both wired and wireless (16-22Mb/s on Comcast).  The only thing I can think of that might give you problem is possibly the cable your using is bad and not supporting the speeds.  I had this happen once to one of my cables.

[richardnau]

Thanks for the suggestion. I've tried several different cables. No change.

[☠]

I get about half my Cable modem's bandwidth on 802.11N if i have WEP or no encryption enabled.

i must use wpa only mode to get the best speeds...then again thats how N was designed


Ubuntu linux
DWA-522 adapter

[richardnau]

I solved my problem.

My ISP provides a service that gives me 20Mbps down but a measly 256kbps up! If I turn on 'traffic shaping' in the router, it restricts each 'application' so that no single application uses all the available bandwidth. The effect is that the acknowledgement packets associated with my download test stream get throttled -- with the result that the download slows down.

Simple solution: turn off upstream 'packet shaping' and I'm instantly back to 20Mbps downloads.

Who'd have thought it?

[AWDL]

Excellent discovery. Good Job.

[ddwinell]

Thats a very limited Upload cap.

[☠]

I solved my problem.

My ISP provides a service that gives me 20Mbps down but a measly 256kbps up! If I turn on 'traffic shaping' in the router, it restricts each 'application' so that no single application uses all the available bandwidth. The effect is that the acknowledgement packets associated with my download test stream get throttled -- with the result that the download slows down.

Simple solution: turn off upstream 'packet shaping' and I'm instantly back to 20Mbps downloads.

Who'd have thought it?

If you configure your Traffic shaping instead of shutting it off, you will get even BETTER speeds

[richardnau]

If you configure your Traffic shaping instead of shutting it off, you will get even BETTER speeds

It certainly is!

[dowood]

If you configure your Traffic shaping instead of shutting it off, you will get even BETTER speeds

So how does one go about configuring the routers traffic shaping specifically?  This is one feature of the DIR-655 I have little understanding about.   

[Lycan]

Check the support site for FAQ's.
I know I've created at least 1.
www.support.dlink.com/products

Remember the higher the QoS priority number the lower outbound prioroity you'll get.

http://www.support.dlink.com/faq/view.asp?prod_id=2485&question=DIR-625%20/%20DIR-635%20/%20DIR-655%20/%20DIR-625_revC

That should help.