[rapidfirerob]

I recently added a Netgear N-300 router to my Dell desktop, less than three years old. The computer is still hard wired into the router, as I am only using the router at this point to stream movies from Netflix onto the tv. Since adding the router into the system, my download speed has slowed from .56MBPS to.20. (Unfortunately I cannot upgrade my speed as I am too far from AT&T's central station. I have DSL service with them.) My upload speed remains unchanged at .32. Is it possible to optimize the router so my speed will return? For now, I have taken the router out of the system. Thanks so much. XP Pro OS, Google Chrome browser.

[JohnWill]

First step is to configure the MTU size in that router to 1492, it's probably currently at 1500. Since you have a DSL connection, that may be the issue.

[rapidfirerob]

Netgear's knowledge base says to download Dr. TCP software, gives me a link. After running the utility, Netgear says to pull down Adapter Settings, select the Ethernet Driver and Adaptor used to connect with the network. Can you please explain how to find what Ethernet Driver and Adaptor I am using?

[TerryNet]

In Device Manager your ethernet adapter (sometimes called Controller) will be listed under Network adapters. Right click on it - Properties - Driver tab - to see what driver is installed.

[rapidfirerob]

I opened TCP software, selected the correct ethernet driver, typed in 1492 in the MTU box, clicked Save, Exit and restarted the computer. My download speed is still .20.

[JohnWill]

Actually, I wanted you to change the MTU size in the router.

[rapidfirerob]

Can you explain how to do that? When I log into the router, there is nothing that says anything about MTU size. This is why I went to the Netgear knowledge base. When I typed in MTU size, what I was told to do is what I did, run this Dr. TCP software, which I thought did change the MTU size in the router. This is all foreign to me.

[JohnWill]

Here's the Netgear N300 User Manual, on page 6-2 the following description applies.

[rapidfirerob]

Done. The download speed is still .20. Rebooted and speed is unchanged. Checked and MTU size is still 1492.

[JohnWill]

What's the exact make and model of the DSL modem? Let's see this when connected directly to the modem.


Hold the Windows key and press R, then type CMD then press Enter to open a command prompt:

In the command prompt window that opens, type type the following command:

Note that there is a space before the /ALL, but there is NOT a space after the / in the following command.

IPCONFIG /ALL

Right click in the command window and choose Select All, then hit Enter to copy the contents to the clipboard.
Paste the results in a message here.

If you are on a machine with no network connection, use a floppy, USB disk, or a CD-RW disk to transfer a text file with the information to allow pasting it here.

[rapidfirerob]

The modem is a Speedstream 4100. I took the router out of the chain, copied and pasted the information into my word processing program and then copied and pasted it here.


Microsoft Windows XP [Version 5.1.2600]
(C) Copyright 1985-2001 Microsoft Corp.

C:\Documents and Settings\Rob Waxman>IPCONFIG /ALL

Windows IP Configuration

Host Name . . . . . . . . . . . . : DJ4BMDG1
Primary Dns Suffix . . . . . . . :
Node Type . . . . . . . . . . . . : Unknown
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No

Ethernet adapter Local Area Connection:

Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Intel(R) 82562V-2 10/100 Network Con
nection
Physical Address. . . . . . . . . : 00-1D-09-9C-9B-34
Dhcp Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
IP Address. . . . . . . . . . . . : 71.141.122.194
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . : 71.141.122.193
DHCP Server . . . . . . . . . . . : 192.168.0.1
DNS Servers . . . . . . . . . . . : 192.168.0.1
192.168.0.1
Lease Obtained. . . . . . . . . . : Sunday, September 12, 2010 9:19:16 P
M
Lease Expires . . . . . . . . . . : Sunday, September 12, 2010 9:29:16 P
M

C:\Documents and Settings\Rob Waxman>

[JohnWill]

Do the following procedure and report the results.


To check the correct or best MTU value try pinging an IP address using the format:

PING <url> –f –l 1472

Start at 1472 and change the end value lower by 8. Repeat until you get the maximum number you can without getting the response ‘Packet needs to be fragmented but DF set.’ Then add back the 28 to that value and that’s the best for the connection.

The <url> is any site that responds to pings, I use google.com.

[rapidfirerob]

I assume this is with the router connected? Just making sure. Can you please explain exactly where spaces are?
Lower the value by 8 and then add back in 28? Is that correct? Thanks for your patience.

[JohnWill]

Yes, this is with the router connected. It might be interesting to see how the bare modem handles this as well.

Put a space between each parameter, i.e.

PING<sp>-f<sp>-l<sp>1472

[rapidfirerob]

My speed without the router is now down to .20. I pinged just the modem using google as the site and got the message at
1472 that you outlined about Packet needs to be fragmented but DF set. I have filters at my phone jacks for my DSL. Could a bad filter cause a slowdown in speed? I don't understand why my speed with just the modem is now slow.