Upload Speeds - With router, slow - Without router; fast?

GeForceX

Supreme [H]ardness
Joined
Mar 19, 2003
Messages
4,172
Hi guys,

Let's see if someone can figure this one out. My dad has been complaining about our cable's inconsistent and low upload speeds (which is max 384 kbps) because it impacts the quality of his videophone sessions which require a minimum of 250 kbps stream. I decided to check into this.

I tested the upload speed while having the router connected and it comes up to be 300~ kbps (37.5 kb/s). Then I unplugged every line that connects to the router except just one computer, the upload comes up to be 315~ kbps (40 kb/s). Not a huge difference. Then I tried to connect directly from the cable modem to the computer, altogether skipping the router, and guess what? I ended up having 380~ kbps (47 kb/s). That's a huge jump.

Please note that I have tested these speeds using speedtest.com over 3 times to ensure there isn't any inconsistency.

Why is my router (DIR-655) causing poor upload performance? On the upside, it hasn't impacted the downstream at all (4800~ kbps / 600~ kb/s). So, what's going on?

Anyone fill me in?

Thanks,
Jeff
 

ocbaud

Supreme [H]ardness
Joined
Nov 3, 2000
Messages
5,906
i'm having the opposite problem. router is causing the download speed to suck, but the upload stays about the same.

my download goes from 8000kbps with the modem directly connected
to
3500kbps with the router inbetween

i have a new router coming tomorrow
 

Zepher

[H]ipster Replacement
Joined
Sep 29, 2001
Messages
19,037
Linksys WRT54G
Firmware Version: v8.00.2
I am supposed to get 2mbps upload.

 

YeOldeStonecat

[H]F Junkie
Joined
Jul 19, 2004
Messages
11,330
Latest firmware on the router?

Try manually setting MTU on the router (1500 for cable)

It's just a pure bridged modem that you're plugging into right? Not a gateway appliance that's already running NAT?
 
Joined
Oct 23, 2005
Messages
670
Do you by chance have QoS set up? Also, are you testing the same pc with it being the only computer connected to the router and the same computer connecting straight to the modem? Also check to see that no one is leeching off your network.
 

GeForceX

Supreme [H]ardness
Joined
Mar 19, 2003
Messages
4,172
Latest firmware on the router?

Try manually setting MTU on the router (1500 for cable)

It's just a pure bridged modem that you're plugging into right? Not a gateway appliance that's already running NAT?

I apologize, I didn't catch this thread - thought it died. :p

Yes, latest firmware and MTU is 1500.

When I was testing the speeds, I tested three scenarios:

1) Router with all computers connected
2) Router with only one computer connected
3) Direct cable modem to one computer

Isn't a router with several DHCP'ed IP's on it considered NAT? Correct me if I'm wrong.

rapperwith1p said:
Do you by chance have QoS set up? Also, are you testing the same pc with it being the only computer connected to the router and the same computer connecting straight to the modem? Also check to see that no one is leeching off your network.

QoS is not on.

No one is leeching off the network.

And to answer your question, yes.
 

msabo

Gawd
Joined
Jun 23, 2008
Messages
632
The performance hit may be coming from TCP. If there were excessive latency throught the router for some reason or data corruption, TCP would react by adjusting its windowing. Do you have any TCP diagnostic tools?
 
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