Linksys Router Slowdown

[dparkinson]

I have a Linksys BEFSR41 v2 cable/dsl router. I have 2 computers hooked up to it and running fine. The problem occurs when b both computers are playing a network intensive game like Unreal Tournament. When both computers are playing over the WAN, my ping rates increase by 2 to 3 times. When one box disconnects. The other box returns to normal. Is there a way I can remedy this?

[dparkinson]

An additional note, I had a PC doing the same thing as this router using the latest version of Sygate and didn't have a problem. There is something going on with this particular router. FYI, my ISP uses PPPoE for authentication.

[dannjr]

Have you ran the tweak test to see if you have to lower the MTU of your machines..
Most routers need to have it lowered...

Does Linky have this problem. I couldn't say. I kept mine for a day, and sent it back. in exchange for a differnt router because I heard of, and read of, these problems with there routers. Most of it was related to the firmware at the time...
I used to run a proxy server similar to your sygate. Proxy server software does have the proper MTU usually and when setup correctly can be faster than a router but its more work.
The router can still be one of the better ways to go...

[ 03-13-2001: Message edited by: dannjr ]

[dparkinson]

First, thank you for responding. I ran the analyzer off this site and received a MTU rating of 1362. Since my connection uses PPPoE, doesn't this number need to go lower instead of higher? Also, I did finally get a response from Linksys technical support to go backwards in firmware revisions. They mentioned that the newer versions provide additional packet checks to insure integrity. I am wondering, the more I pass through it, the slower it goes because of its 512k buffer...

[dannjr]

try setting the MTU in your machines to 1486 or even 1476...
on the Ugate 3200 and the Linky when you set it down in the machine the test comes back with a much better MTU this is probably due to the LAN managment of the router...
I have mine set to 1486 and this is what gets returned by the test here..
TCP options string = 0204059c010303030101080a000000000000000001010402

MTU = 1476
MTU is not fully optimized for broadband. Consider increasing your MTU to 1500 for better throughput. If you are using a router, it could be limiting your MTU regardless of Registry settings.

MSS = 1436
Maximum useful data in each packet = 1424, which is less than MSS because of Timestamps, or other TCP/IP options used.

setting it to 1476 seems to make more sence but I get this same reading if its set to 1492 the second I go above that it reads 1362
I get the same when I run a packet sniffer

[dparkinson]

I will try changing the MTU right now...but do you recommend another router that supports PPPoE which may not have this problem?

[dparkinson]

I set my MTU size like you recommended, but I didn't get any improvement. Anybody with any other suggestions or experience with Linky?

[dannjr]

Originally posted by dparkinson:
I will try changing the MTU right now...but do you recommend another router that supports PPPoE which may not have this problem?

Just the Ugate 3200 it dosn't seem to slow down and at least tech support listens and helps without real long waits...

Whats the Rwin set at in the machines ?
post your tweak test maybe thats the answer..
Plus besides TCP what other Protocols are you running

[ 03-13-2001: Message edited by: dannjr ]

[dparkinson]

I took the MaxMTU setting out of the registry. It wasn't doing anything good...here are the results of the analysis:

TCP options string = 0204052a01010402

MTU = 1362
MTU is not fully optimized for broadband. Consider increasing your MTU to 1500 for better throughput.

MSS = 1322
Maximum useful data in each packet = 1322, which is equal to MSS.
MSS is not fully optimized for broadband (although it might work well for slower connections). Consider increasing your MTU value.

Default Receive Window (RWIN) = 17186
RWIN Scaling (RFC1323) = 0 bits
Unscaled Receive Window = 17186
RWIN is a multiple of MSS
Other values for RWIN that might work well with your current MTU/MSS:
507648 (MSS x 48 * scale factor of 8)
253824 (MSS x 48 * scale factor of 4)
126912 (MSS x 48 * scale factor of 2)
63456 (MSS x 48)

bandwidth * delay product:
Your RcvWindow limits you to: 687.44 kbps (85.93 KBytes/s) @ 200ms
Your RcvWindow limits you to: 274.976 kbps (34.372 KBytes/s) @ 500ms
Consider increasing your RWIN value to optimize TCP/IP for broadband.

MTU Discovery (RFC1191) = ON

Time to live left = 118 hops
TTL value is ok.

Timestamps (RFC1323) = OFF

Selective Acknowledgements (RFC2018) = ON

IP type of service field (RFC1349)= 00000000

[Orangachu]

Originally posted by dparkinson:
I will try changing the MTU right now...but do you recommend another router that supports PPPoE which may not have this problem?

I would suggest, going to the Linksys site and upgrading the Firmware (not the 'software'. The latest version has full PPOE support.

I have had said router for some time, and have updated twice (although, they say if it is having no problems, don't, I had no problems and did, and still had no problems, unless you consider a slight increase in speed a problem)

[dannjr]

Heres something to look at besides updateing your firmware which if they have that you should do..
But I ran a test on the tweak tester with Time stamps off in win2k and i probably should have removed the other two settings for this example but there was a big difference just in the Rwin...

turn timestamps on will make a difference in a PPPoE connection
thats this seting
Tcp1323Opts=dword setting is three 3

First one with time stamps off
TCP options string = 0204059c01010402

MTU = 1476
MTU is not fully optimized for broadband. Consider increasing your MTU to 1500 for better throughput. If you are using a router, it could be limiting your MTU regardless of Registry settings.

MSS = 1436
Maximum useful data in each packet = 1436, which is equal to MSS.
MSS is not fully optimized for broadband (although it might work well for slower connections). Consider increasing your MTU value.

Default Receive Window (RWIN) = 65535
RWIN Scaling (RFC1323) = 0 bits
Unscaled Receive Window = 65535
Note: Under Windows 9x, if you have RWIN set to any other value, and the Analyzer reports 65535 you might need to install the MS Vtcp386 fix.
For optimum performance, consider changing RWIN to a multiple of MSS.
Other values for RWIN that might work well with your current MTU/MSS:
505472 (MSS x 44 * scale factor of 8)
252736 (MSS x 44 * scale factor of 4)
126368 (MSS x 44 * scale factor of 2)
63184 (MSS x 44)

bandwidth * delay product:
Your RcvWindow limits you to: 2621.4 kbps (327.675 KBytes/s) @ 200ms
Your RcvWindow limits you to: 1048.56 kbps (131.07 KBytes/s) @ 500ms

MTU Discovery (RFC1191) = ON

Time to live left = 240 hops
TTL value seems to be too large, packets will not be discarded in a reasonable amont of time. Consider decreasing TTL.

Timestamps (RFC1323) = OFF

Selective Acknowledgements (RFC2018) = ON


This one Time stamps on

TCP options string = 0204059c010303030101080a000000000000000001010402

MTU = 1476
MTU is not fully optimized for broadband. Consider increasing your MTU to 1500 for better throughput. If you are using a router, it could be limiting your MTU regardless of Registry settings.

MSS = 1436
Maximum useful data in each packet = 1424, which is less than MSS because of Timestamps, or other TCP/IP options used.
MSS is not fully optimized for broadband (although it might work well for slower connections). Consider increasing your MTU value.

Default Receive Window (RWIN) = 471712
RWIN Scaling (RFC1323) = 3 bits
Unscaled Receive Window = 58964
For optimum performance, consider changing RWIN to a multiple of MSS.
Other values for RWIN that might work well with your current MTU/MSS:
505472 (MSS x 44 * scale factor of 8)
252736 (MSS x 44 * scale factor of 4)
126368 (MSS x 44 * scale factor of 2)
63184 (MSS x 44)

bandwidth * delay product:
Your RcvWindow limits you to: 18868.48 kbps (2358.56 KBytes/s) @ 200ms
Your RcvWindow limits you to: 7547.392 kbps (943.424 KBytes/s) @ 500ms

MTU Discovery (RFC1191) = ON

Time to live left = 240 hops
TTL value seems to be too large, packets will not be discarded in a reasonable amont of time. Consider decreasing TTL.

Timestamps (RFC1323) = ON
Note: Timestamps add 12 bytes to the TCP header of each packet, reducing the space available for useful data.

Selective Acknowledgements (RFC2018) = ON

[dparkinson]

I have the latest firmware installed. So that isn't the prob...Ok guys...BIG UPDATE:

I went to my friends house, we both use SWBELL ADSL service. I got it after they put out the PPPoE stuff. He got his before, so he doesn't use it. Well, I hooked my computer up to his Linksys Router, and poof! Check these numbers out:

TCP options string = 020405b401010402

MTU = 1500
MTU is fully optimized for broadband.

MSS = 1460
Maximum useful data in each packet = 1460, which is equal to MSS.

Default Receive Window (RWIN) = 17520
RWIN Scaling (RFC1323) = 0 bits
Unscaled Receive Window = 17520
RWIN is a multiple of MSS
Other values for RWIN that might work well with your current MTU/MSS:
513920 (MSS x 44 * scale factor of 8)
256960 (MSS x 44 * scale factor of 4)
128480 (MSS x 44 * scale factor of 2)
64240 (MSS x 44)

bandwidth * delay product:
Your RcvWindow limits you to: 700.8 kbps (87.6 KBytes/s) @ 200ms
Your RcvWindow limits you to: 280.32 kbps (35.04 KBytes/s) @ 500ms
Consider increasing your RWIN value to optimize TCP/IP for broadband.

MTU Discovery (RFC1191) = ON

Time to live left = 118 hops
TTL value is ok.

Timestamps (RFC1323) = OFF

Selective Acknowledgements (RFC2018) = ON

IP type of service field (RFC1349)= 00000000

I am running at top speed. The only conclusion I can draw is that the PPPoE is messing things up and I really need to figure out how to tweak my PPPoE on both my boxes. I will turn my timestamps on to try to help it...any other suggestions anyone?

[ 03-14-2001: Message edited by: dparkinson ]

[dannjr]

PPPoE has more over head than a direct connection on a static line... With the new firmware on your connection with the MTU set down to 1492 or lower is it still doing the 1362....

I wish I had your buddys connection I bet you do to...
See if you can get your numbers up by lowering the MTU the rest will start to improve then..
once thats set you can get your Rwin right

[dparkinson]

UPDATE: Here are the numbers on my buddies connection with my router...

TCP options string = 0204059c01010402

MTU = 1476
MTU is not fully optimized for broadband. Consider increasing your MTU to 1500 for better throughput. If you are using a router, it could be limiting your MTU regardless of Registry settings.

MSS = 1436
Maximum useful data in each packet = 1436, which is equal to MSS.
MSS is not fully optimized for broadband (although it might work well for slower connections). Consider increasing your MTU value.

Default Receive Window (RWIN) = 17232
RWIN Scaling (RFC1323) = 0 bits
Unscaled Receive Window = 17232
RWIN is a multiple of MSS
Other values for RWIN that might work well with your current MTU/MSS:
505472 (MSS x 44 * scale factor of 8)
252736 (MSS x 44 * scale factor of 4)
126368 (MSS x 44 * scale factor of 2)
63184 (MSS x 44)

bandwidth * delay product:
Your RcvWindow limits you to: 689.28 kbps (86.16 KBytes/s) @ 200ms
Your RcvWindow limits you to: 275.712 kbps (34.464 KBytes/s) @ 500ms
Consider increasing your RWIN value to optimize TCP/IP for broadband.

MTU Discovery (RFC1191) = ON

Time to live left = 118 hops
TTL value is ok.

Timestamps (RFC1323) = OFF

Selective Acknowledgements (RFC2018) = ON

IP type of service field (RFC1349)= 00000000

As you can see, they are a little off, but we don't suffer any slowdown whatsoever. This concludes that it is the way Linksys has Linky configured to handle PPPoE. So the question is: WTF do I do? Go back to a proxy computer? The EnterNet 300 PPPoE software that SWBELL gave me works just fine...I just need to tweak the router...and you can't tweak the PPPoE on the router...

[dparkinson]

when I set the MTU to 1476, it doesn't do the 1382 thing anymore. sorry I didn't answer your question before...

[dparkinson]

also, to make sure I am doing this stuff right, could someone please point me in the direction of how to change these settings? (timestamp,MTU)