New Uverse customer, MTU, TCP Optimizer?

California Roll

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Nov 8, 2004
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I recently had 24/3 Uverse installed and everything seems to work great. Tech said I'm only 700 feet away and had only 2% signal loss when they tested the line. Multiple speedtest.net tests confirmed 23/2.9, so I'm ecstatic.

I used TCP optimizer previously for my old 1.5mpbs connection. Do I optimize again or just leave it? I've used the great guide at ezlan.net to optimize my previous internet connections but I'm not sure which values to use for Uverse.
 

California Roll

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Nov 8, 2004
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Instead of Dr.TCP that is mentioned in ezlan.net use this one.

http://www.speedguide.net/files/TCPOptimizer.exe

You can try MTU 1492 or 1400 and see which one works better on your connection.

As for RCwin use 1027840

Check the box that says Modify all Network Adapters.


:cool:

Awesome, thanks again Jack :) I was looking forward to your reply.

edit: one more note, I have a gigabit switch hooked up to the router with 3 gigabit enabled pc's connected. Does this change any of the values you mentioned?
 
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JackMDS

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Oct 25, 1999
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The high RCwin probably will improve the Giga traffic too.

If your Giga switch is Jumbo Frames capable you can try MTU of 9000 too.

In each case measure carefully local and internet transfer, and choose the combo that is best for your network.

:cool:
 

California Roll

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Nov 8, 2004
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The high RCwin probably will improve the Giga traffic too.

If your Giga switch is Jumbo Frames capable you can try MTU of 9000 too.

In each case measure carefully local and internet transfer, and choose the combo that is best for your network.

:cool:

Thanks again. Yes, switch and all pc's are jumbo frames capable.

I'll use RCwin 1027840. MTU 1492, 1400, 9000 and test all 3.
 

ScottMac

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Mar 19, 2001
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U-Verse is straight Ethernet and supports a full MTU of 1500 bytes.

If you are using a VPN, or some other encrypted-enabled schemes, then you might want to drop the MTU ... otherwise, you should do best at 1500.

Where most xDSL is ATM based, and use a 1492 MAX MTU, U-Verse (and the newer IPDSLAM services) are full Ethernet frames (1500).
 

California Roll

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I was fiddling around in the router/modem settings and I noticed "Upstream MTU = 1500".

I don't use VPN at all.
 

California Roll

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Just to update my thread, I settled on MTU 1500, RCwin 1027840. To be honest, there was do discernible difference in my previous 1.5mbps internet settings and my current one.
 

spidey07

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Aug 4, 2000
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There shouldn't be. The window size is what affects it the most on high bandwidth, high latency network (consumer broadband). At 1 meg window you only need to ACK every 1 MB of data. TCP will scale down the window if there is any packet loss anyway so much better to start off high. Use lower if you have much packet loss, which is rare even for consumer broadband networks.
 

wlee

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Oct 10, 1999
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I think it would also depend on what OS you are using. I thought that Win Vista and 7 have auto-scaling rwin. I have found that dropping the MTU to 1472 on cable and 1454 on DSL seems to clear up any probs with failed POP and SMTP sessions.
 

JackMDS

Elite Member
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Oct 25, 1999
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I think it would also depend on what OS you are using. I thought that Win Vista and 7 have auto-scaling rwin. I have found that dropping the MTU to 1472 on cable and 1454 on DSL seems to clear up any probs with failed POP and SMTP sessions.

The minute tuning is a matter of the specific Network/Hardware/OS.

That is why people have to try few settings, and Not just copy from someone else.



:cool: