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#304416 - 26/11/2007 22:39 fast cable router
pca
old hand

Registered: 20/07/1999
Posts: 1102
Loc: UK
Hi.

I have a problem that I'm hoping someone in empeg-land may have the answer to.

Telewest/Blueyonder/Virgin Media (delete as applicable) have recently upgraded the cable provided internet I'm using to 20Mbits. Woohoo. Unfortunately, in so doing they have broken compatiblilty with my firewall/router (an oldish, but not elderly BEFSR41) The net result is that my link to the rest of the world is now running at 4Mb after the upgrade rather than the 10Mb it was before

It took a while to prove it was the router, mainly because I didn't think of it! I tested everything else to the hilt, but it took a couple of days before I thought "Ah. I wonder..." and plugged a laptop directly into the modem. Bingo, 18Mb+ download speed, much more like it. Router goes back in, 4Mb.

So, my question is this: Which router/firewall (no wireless required) will not only work well at 20Mb, but is sufficiently future-proofed to work at the 50Mb+ they're now insisting they'll be rolling out by the end of next year? I would prefer not to spend a huge amount of money, but I want to get a good one.

pca
_________________________
Experience is what you get just after it would have helped...

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#304417 - 26/11/2007 23:19 Re: fast cable router [Re: pca]
tfabris
carpal tunnel

Registered: 20/12/1999
Posts: 31596
Loc: Seattle, WA
Aw, it's a shame that the '41 isn't working any more. Those are such workhorses! They're everywhere!

I'm sure you've done this already, but have you checked to see whether there's a firmware update for the '41?
_________________________
Tony Fabris

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#304418 - 26/11/2007 23:42 Re: fast cable router [Re: tfabris]
pca
old hand

Registered: 20/07/1999
Posts: 1102
Loc: UK
Yes, applied the latest firmware. No difference.

pca
_________________________
Experience is what you get just after it would have helped...

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#304419 - 27/11/2007 00:16 Re: fast cable router [Re: pca]
wfaulk
carpal tunnel

Registered: 25/12/2000
Posts: 16706
Loc: Raleigh, NC US
That doesn't make much sense. There shouldn't be any compatibility issue, as it's just 10/100 ethernet all around, and those problems were well sorted out by the time that router was released. I was going to ask if maybe the internet side of the router was 10Mbps only, saving Linksys 5¢, but the spec sheet says all ports are 10/100.

Is it possible that you have that port forced to a specific speed/duplex setting that now needs to be updated?

Can you try putting a switch between the modem and the router?


Edited by wfaulk (27/11/2007 00:20)
_________________________
Bitt Faulk

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#304420 - 27/11/2007 05:17 Re: fast cable router [Re: pca]
altman
carpal tunnel

Registered: 19/05/1999
Posts: 3457
Loc: Palo Alto, CA
Expensive, and it probably can't move the packets fast enough to justify having it, but the Apple Airport Extreme has:

a) 3 port gigabit local-side hub
b) Gigabit WAN port

On the wireless downside it won't let you do plain WEP networks - WPA or "transitional" WPA/WEP that I never got to work right, so you're SOL on old wireless gear. It also doesn't have a clone mac address option for the WAN port which is irritating, but it turned out I didn't need this anyway.

My cable modem connection in Cambridge is going seriously flaky when pushed, but I believe that's the 3Com CMX finally giving up the ghost. Any piece of equipment whose *power led* fails is obviously due to be replaced

What was most annoying was that though I *paid for* the modem - there was no free or subsidised modem offer back then in the early days of UK cable modems - NTL/etc refused to give me a new one unless they could send an engineer round to diagnose my current modem (who, no doubt, would have said "oh, it's working fine" as it only drops out when you really saturate it - again since they moved me to 20Mbit). They asked what model it was and got very confused as they'd never heard of a CMX...

Anyway, oh for decent speed internet. DSL here is still 1.5Mbit max, though cable is 6-10ish!

Hugo

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#304421 - 27/11/2007 06:41 Re: fast cable router [Re: pca]
Shonky
pooh-bah

Registered: 12/01/2002
Posts: 2009
Loc: Brisbane, Australia
I'd be interested in why overall throughput slowed down just because the ISP/modem side sped up.
_________________________
Christian
#40104192 120Gb (no longer in my E36 M3, won't fit the E46 M3)

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#304422 - 27/11/2007 13:09 Re: fast cable router [Re: Shonky]
wfaulk
carpal tunnel

Registered: 25/12/2000
Posts: 16706
Loc: Raleigh, NC US
That's what's leading me to think that it's an ethernet speed/duplex issue. I have never heard of any other instances in the last 10 years where ethernet compatibility fails.
_________________________
Bitt Faulk

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#304423 - 27/11/2007 13:50 Re: fast cable router [Re: pca]
mlord
carpal tunnel

Registered: 29/08/2000
Posts: 14491
Loc: Canada
Quote:
Yes, applied the latest firmware. No difference.

pca


Which Linux kernel version does it use ? It could just be a victim of incorrect TCP window scaling settings, something that may be easily fixed.

-ml

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#304424 - 27/11/2007 13:57 Re: fast cable router [Re: mlord]
mlord
carpal tunnel

Registered: 29/08/2000
Posts: 14491
Loc: Canada
Quote:
Quote:
Yes, applied the latest firmware. No difference.

pca


Which Linux kernel version does it use ? It could just be a victim of incorrect TCP window scaling settings, something that may be easily fixed.



MMmm scratch that. This beast is too ancient for any of the modern tweakable firmware replacements.

How about a nice, hackable (or not), WRT54GS router/firewall/Wifi unit?

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#304425 - 27/11/2007 13:59 Re: fast cable router [Re: pca]
mlord
carpal tunnel

Registered: 29/08/2000
Posts: 14491
Loc: Canada
Quote:
The net result is that my link to the rest of the world is now running at 4Mb after the upgrade rather than the 10Mb it was before


Here's an idea: try *reducing* the max packet size (MTU, MRU) to, say, 1400 bytes.

Just try it.

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#304426 - 27/11/2007 14:01 Re: fast cable router [Re: pca]
mlord
carpal tunnel

Registered: 29/08/2000
Posts: 14491
Loc: Canada
Quote:

So, my question is this: Which router/firewall (no wireless required) will not only work well at 20Mb, but is sufficiently future-proofed to work at the 50Mb+ they're now insisting they'll be rolling out by the end of next year?


Note that this is easy to test/measure, by connecting the upstream port to another PC (running a Web/FTP server) instead of to the internet.

Cheers

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#304427 - 28/11/2007 14:06 Re: fast cable router [Re: mlord]
pca
old hand

Registered: 20/07/1999
Posts: 1102
Loc: UK
OK, things are getting somewhat strange.

I couldn't adjust the MTU settings on the BEFSR41 as it doesn't seem to have them. However, I found a number of reports from others in the same situation showing that the throughput of the WAN port on this particular router isn't very high. After a lot of research I settled on the Netgear WNR854T router/AP as having a very high (>80Mbit) WAN-to-LAN rate, and a reasonable cost. It also has 802.11n, which I don't need as I'm running 802.11a via an SMC AP. I ordered one yesterday, and it turned up today.

It took about half an hour to get it configured correctly (has anyone noticed how recent routers, etc, seem to be incredibly slow when updating settings compared to older ones like the BEFSR41?) and in the process I made the interesting discovery that Virgin appear to assign IP based on the MAC address of whatever is connected to the cable modem I set the MAC to be the same as the old router, to keep the tests consistent.

The end result of this was a working link, and I tried a speed test with www.speedtest.net with barely contained excitement. Would it beat my previous speed of 4.5Mbit?

It did. With 6Mbit! Damn. I tried all three windows 2000 machines connected to the router, which vary from a very old shuttle with an Athlon XP 2200 to a shiny new Pentium 4 3GHz box, and got more or less exactly the same figure with all of them. I then tried the XP laptop, out of curiosity. 15.5Mbit? What the hell?

Admittedly this is a 2GHz core2 Duo machine, pretty fast, but I wouldn't have though so much faster than the 3GHz P4 to have processor speed make that much of a difference. But I'm not sure why Win2K would be less than half the speed of XP for network transfer either. So I tried my linux dev box as well. 13.5Mbit. Even odder.

It definitely seems to be either the OS or perhaps some application on the 2000 machines that's not present on the XP or Kubuntu installations, especially as the linux box is the slowest hardware of all, being an ancient 1.33GHz Athlon. However, all the windows machines have pretty much all the same security apps, drivers for dongles, browsers, etc. I performed the test using the same version of Firefox in each case, and the results are completely repeatable.

I have also tried putting the old router back in and testing again. 4Mbit across the board, which shows THAT speed is a router issue. I have also tried setting the router MTU value on the Netgear to 1472, which is what Virgin seem to be using, and it made a very small difference to the XP connection speed (slightly faster) but had no effect on the windows 2000 speed. The obvious conclusion is that the windows 2000 installations have much slower network transfer rates than either XP or Kubuntu, but why? Anyone?

pca
_________________________
Experience is what you get just after it would have helped...

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#304428 - 28/11/2007 14:13 Re: fast cable router [Re: pca]
wfaulk
carpal tunnel

Registered: 25/12/2000
Posts: 16706
Loc: Raleigh, NC US
Okay, so now it's Windows' weird network settings. Try disabling Path MTU discovery?
_________________________
Bitt Faulk

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#304429 - 28/11/2007 14:28 Re: fast cable router [Re: wfaulk]
Schido
enthusiast

Registered: 29/03/2005
Posts: 364
Loc: Probably lost somewhere in Wal...
http://www.dslreports.com/tweaks is an easy way to find out if your rwin and mtu settings are causing problems
_________________________
Empeg Mk1 #00177, 2.00 final, hijack 4.76

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#304430 - 28/11/2007 14:44 Re: fast cable router [Re: wfaulk]
pca
old hand

Registered: 20/07/1999
Posts: 1102
Loc: UK
It was already off (no registry key, does that mean it defaults off or on?) and I turned it on for one of the machines. It made no difference. I'll try explicitly setting it the other way to see what happens.

pca

Nope, no difference.


Edited by pca (28/11/2007 14:57)
_________________________
Experience is what you get just after it would have helped...

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#304431 - 28/11/2007 15:26 Re: fast cable router [Re: pca]
mlord
carpal tunnel

Registered: 29/08/2000
Posts: 14491
Loc: Canada
Quote:

I have also tried putting the old router back in and testing again. 4Mbit across the board, which shows THAT speed is a router issue. I have also tried setting the router MTU value on the Netgear to 1472, which is what Virgin seem to be using, and it made a very small difference to the XP connection speed (slightly faster) but had no effect on the windows 2000 speed. The obvious conclusion is that the windows 2000 installations have much slower network transfer rates than either XP or Kubuntu, but why? Anyone?

pca



Google for Dr.TCP, and install/run it on those old boxes. It's probably just a low MTU on Win2000 or something.

The Kubuntu box should be able to do better than the 13.5mb/s as well, probably due to old defaults for TCP window size and/or scaling. A kernel newer than 2.6.18 will have faster defaults.

Cheers

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#304432 - 28/11/2007 16:06 Re: fast cable router [Re: mlord]
pca
old hand

Registered: 20/07/1999
Posts: 1102
Loc: UK
Quote:

Google for Dr.TCP, and install/run it on those old boxes. It's probably just a low MTU on Win2000 or something.


That did it. I set the MTU to 1500 and the RWIN to 192096, as suggested by dslreports.com, and the speed jumped to 15Mbits. Thanks to everyone.

Pca

changed RWIN to 384192 and the speed went to 16.5Mbits. Making it even larger slowed it down again, so I went back


Edited by pca (28/11/2007 16:23)
_________________________
Experience is what you get just after it would have helped...

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#304433 - 28/11/2007 16:45 Re: fast cable router [Re: pca]
mlord
carpal tunnel

Registered: 29/08/2000
Posts: 14491
Loc: Canada
Quote:
Quote:

Google for Dr.TCP, and install/run it on those old boxes. It's probably just a low MTU on Win2000 or something.


That did it. I set the MTU to 1500 and the RWIN to 192096, as suggested by dslreports.com, and the speed jumped to 15Mbits. Thanks to everyone.

Pca

changed RWIN to 384192 and the speed went to 16.5Mbits. Making it even larger slowed it down again, so I went back


The equivalent settings for the Kubuntu box are under /proc/sys/net/ipv4/ :

echo 1 > /proc/sys/net/ipv4/tcp_window_scaling
echo "4096 16384 65536" > /proc/sys/net/ipv4/tcp_wmem

Larger values for that third parameter (65536) will give similar behaviour to the 192096 or 384192 numbers you used for Win2000.

You can make the changes permanent by also entering them into /etc/sysctl.conf, like this:

net.ipv4.tcp_window_scaling=1
net.ipv4.tcp_wmem=4096 16384 65536

Cheers


Edited by mlord (28/11/2007 16:46)

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#304434 - 28/11/2007 16:49 Re: fast cable router [Re: pca]
mlord
carpal tunnel

Registered: 29/08/2000
Posts: 14491
Loc: Canada
Quote:

That did it. I set the MTU to 1500 and the RWIN to 192096, as suggested by dslreports.com, and the speed jumped to 15Mbits. Thanks to everyone.



While it's still fresh in your mind, you should now go back and change that MTU to 1476. Otherwise you will be very confused some day in the future when sending email from that machine --> any message that exceeds one packet will probably fail until you fix the MTU.

Cheers

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#304435 - 28/11/2007 16:49 Re: fast cable router [Re: pca]
andym
carpal tunnel

Registered: 17/01/2002
Posts: 3996
Loc: Manchester UK
Quote:
and in the process I made the interesting discovery that Virgin appear to assign IP based on the MAC address of whatever is connected to the cable modem I set the MAC to be the same as the old router, to keep the tests consistent.


When I had a cable modem way back in 2001 the MAC address was used as a authentication feature. The cable modem was effectively paired with the network card. Changing the network card or putting a router in instead resulted in a call to ntl to change the MAC address they had on file...... actually when I added the router I just gave it the MAC address of the network card it replaced, so it just worked.
_________________________
Cheers,

Andy M

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#304436 - 28/11/2007 16:50 Re: fast cable router [Re: pca]
tfabris
carpal tunnel

Registered: 20/12/1999
Posts: 31596
Loc: Seattle, WA
Quote:
That did it. I set the MTU to 1500 and the RWIN to 192096, as suggested by dslreports.com, and the speed jumped to 15Mbits. Thanks to everyone.


Now the question is, do you get the same results if you plug the '41 back in the chain?
_________________________
Tony Fabris

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#304437 - 30/11/2007 02:07 Re: fast cable router [Re: pca]
wfaulk
carpal tunnel

Registered: 25/12/2000
Posts: 16706
Loc: Raleigh, NC US
Well, I made some changes to my system with Dr. TCP based on information I found here, and it definitely increased my download speeds. At least when it could actually connect to anything. It made my whole network connection completely unreliable. It'll download at like 9Mbps for a while, and then just nothing.

I'm still trying to tweak it to get it back so that it works properly again, but in the mean time, I managed to lose an eBay auction because I couldn't get to the damned site. Very frustrated right now.
_________________________
Bitt Faulk

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#304438 - 30/11/2007 02:29 Re: fast cable router [Re: wfaulk]
DWallach
carpal tunnel

Registered: 30/04/2000
Posts: 3810
Speaking of speed...

I'll shortly be setting up a gigabit wired network at my new house. I want to do the whole jumbo packet thing, now that it's become cheap to get 8-port switches that support it and it seems to make a sizable performance difference for file servers. The rub: if you try sending a jumbo frame to somebody who can't handle it, they just drop it. So, how am I supposed to integrate this? My concern is that my WAN/LAN gateway and/or wireless base station might drop jumbo frames if they're not jumbo-aware or something.

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#304439 - 30/11/2007 13:17 Re: fast cable router [Re: DWallach]
mlord
carpal tunnel

Registered: 29/08/2000
Posts: 14491
Loc: Canada
Presumably you are also aware of the huge power waste that GigE incurs?

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#304440 - 30/11/2007 13:28 Re: fast cable router [Re: mlord]
mlord
carpal tunnel

Registered: 29/08/2000
Posts: 14491
Loc: Canada
Quote:
Presumably you are also aware of the huge power waste that GigE incurs?


GigE power consumption is typically 1->3 watts per port, at each end of the link.

By comparison, the new 24-port 10/100 switch that we just installed here consumes a mere 3W total with most ports idle, and a max of only 6.5W with all 24 ports active.

Measured and verified by me.

EDIT: The same switch was also available with 2 GigE ports (26 ports in total), but we passed on that because the overall power consumption *doubled* to 12.5W. /EDIT

Cheers

Preserving the planet has to begin somewhere.


Edited by mlord (30/11/2007 13:31)

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#304441 - 30/11/2007 13:40 Re: fast cable router [Re: mlord]
peter
carpal tunnel

Registered: 13/07/2000
Posts: 4180
Loc: Cambridge, England
Quote:
GigE power consumption is typically 1->3 watts per port, at each end of the link.

By comparison, the new 24-port 10/100 switch that we just installed here consumes a mere 3W total with most ports idle, and a max of only 6.5W with all 24 ports active.

But the GigE one is ten times faster, so spends 1/10 as much time transmitting or receiving. That makes GigE at 1-3W/port not much different from 100Mbit at 0.25W/port, if you look at power used per bit.

Peter

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#304442 - 30/11/2007 14:07 Re: fast cable router [Re: peter]
mlord
carpal tunnel

Registered: 29/08/2000
Posts: 14491
Loc: Canada
Quote:
Quote:
GigE power consumption is typically 1->3 watts per port, at each end of the link.

By comparison, the new 24-port 10/100 switch that we just installed here consumes a mere 3W total with most ports idle, and a max of only 6.5W with all 24 ports active.

But the GigE one is ten times faster, so spends 1/10 as much time transmitting or receiving. That makes GigE at 1-3W/port not much different from 100Mbit at 0.25W/port, if you look at power used per bit.

Peter


That would be true, if the switches and interfaces were all powered off between packets.

Dream on.

Meanwhile, that's 26kWH per GigE port per year.

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#304443 - 30/11/2007 14:56 Re: fast cable router [Re: wfaulk]
tfabris
carpal tunnel

Registered: 20/12/1999
Posts: 31596
Loc: Seattle, WA
Quote:
It made my whole network connection completely unreliable. It'll download at like 9Mbps for a while, and then just nothing.


Yeah, those network tweakers always scared me for that very reason. Back in the dial-up days, I tried one of those things once in an attempt to get my internet gaming ping times down, and had similar results.
_________________________
Tony Fabris

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#304444 - 30/11/2007 15:18 Re: fast cable router [Re: mlord]
drakino
carpal tunnel

Registered: 08/06/1999
Posts: 7868
Quote:
That would be true, if the switches and interfaces were all powered off between packets.

Dream on.


Looks lke the IEEE is working on this based on this story. While it doesn't completely power down, the idea is to run the link at the minimum speed needed, so when idle the ports are throttled down to 10mbit.

I'm also wondering about your GigE power usage numbers of 1w, as I can find several product announcements of newer lower power GigE chips, with one of those dating back to 2002. Are manufacturers just being really slow on switching to new chips, or being cheep?

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#304445 - 30/11/2007 16:52 Re: fast cable router [Re: mlord]
peter
carpal tunnel

Registered: 13/07/2000
Posts: 4180
Loc: Cambridge, England
Quote:
That would be true, if the switches and interfaces were all powered off between packets.

Dream on.

Well, I guess I'm assuming that most of the power use is in the line drivers. In all varieties of Ethernet, from 10base2 to 1000baseT, the line drivers are powered off, not merely between packets, but also between bits. That's how the collision detection works. (In practice, all GigE equipment seems to be full-duplex and switched, so no collisions happen. But the standard allows for half-duplex and for hubs.)

Peter

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