Will this really help "Dial Up Modem" Performance?

[carson]

Wanted to check here before trying. Maybe someone has experience or has the knowledge to read and confirm or refute. Thanks for any comments.*****

***Begin*** Optimizing Dial-Up Modem Connection Speed (Windows 9x/Me)
By optimizing the MaxMTU & MaxMSS settings along with the RWIN and TTL settings you can increase dialup modem connection reliability and performance by as much as 200%.
What is the MTU and MSS?
MTU stands for Maximum Transmission Unit and in basic terms, it defines the maximum size of a packet that can be transferred in one frame over a network.
MSS or Maximum Segment Size defines how much actual data can put in that packet, and it is therefore a marginally smaller value than MTU to allow for packet addressing and other information.
Why do the default values need to be changed?
By default Windows hard codes the value of MTU to equal 1500 bytes. This value is adequate for normal LAN networking, but when your connecting to the Internet with a modem this value is too high. This can show itself in different ways, the most noticeable affect is less than peak performance.
By adjusting this value to more closely match the requirements of a modem Internet connection huge performance gains can be achieved.
Below are the instructions on how to modify these values for yourself. Please remember though, modifying the Windows registry is not for the faint hearted. Always remember to back it up first!
1. To change the settings you first have to find the details of your Dial-Up Adapter.
2. Find the key HKEY_LOCAL_MACHINE\Enum\Root\Net and within there will be one or more sub-keys such as 0000, 0001 ...
3. Open each key and find the one that contains the value of 'DeviceDesc' equal to 'Dial-Up Adapter'.
4. Within that key there will also be another sub-key named 'Bindings'. Open the 'Bindings' sub-key and you will find a string name like 'MSTCP\0000'. Take note of the four digit number after 'MSTCP' (in this case 0000) and use it in the next step.
5. Now go to the key 'HKEY_LOCAL_MACHINE\Enum\Network\MSTCP' and expand the sub-key with the same four digit number as from the previous step.
6. In this key you will find a value called 'Driver' and it will be equal to something similar to 'NetTrans\0002'. Take note of this four digit number (in this case 0002) and use it in the next step.
7. Now open the key [HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Class\NetTrans] below there will be one or more sub-key's. Expand the key with the name equal to the four digit number from the previous step.
8. Within this key create a new string value named 'MaxMTU' and set it to '576', and also add a string value named 'MaxMSS' and set it to '536'.
9. Then exit the registry and restart your computer.***END

Think it will make a difference or enough to try? Or could it cause a screw-up?
Thanks again...

[kallikru]

Well, it MAY speed up your connection. Unless you have an extremely bad setup it will certainly NOT speed up your connection by 200%. A more realistic figure may be 5 - 20% - windows 98's default settings are not that bad. But even that may be worth a try.....

But be sure to back up your registry before you attempt anything, and make sure you know how to restore the registry if you're not satisfied with the results.

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Karl, Denmark
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"..and may The Force be with you too..."

[steved]

It certainly looks like it might make a difference...THe following below is probably more straightforward though....and it works for both modem and ISDN. I agree with Kallikru that it will not increase your speed by 200%!!

HKEY_CURRENT_USER>
Software>
Microsoft>
Windows>
CurrentVersion>
Internet Settings>

Within the right hand window of RegEdit you will see there are two strings named MaxConnectionsPerServer and MaxConnectionsPerl_OServer, if these are not there then see below. Click on the first one, MaxConnectionsPerServer and then with the right mouse button click your right mouse button and then select Modify. A window will pop up at this point and you need to change the Value data to 6. Make sure at this point that Decimal is selected to the right. Even if you did not select Decimal, it would not matter because this will be the same as Hexadecimal unless it was over 10. So just ensure that Decimal is selected and it contains a value of 6. Now, Click ok and do exactly the same for the other registry entry called MaxConnectionsPerl_OServer.

If you find that 1 or both of these registry entries are no in your registry, then you will have to add them manually. To do this you need to move your mouse over to some white space in the right hand side of the registry editor. Right click and select the new option and then select DWORD Value. Now enter MaxConnectionsPerServer as the string name and then press the return key. Now repeat this process for MaxConnectionsPerl_OServer as the string name. Now modify these entries using the procedure above.

[Herring]

Changing the settings can definitely make a big difference, depending on your modem and your actual phone line quality. When I had my 28.8 modem, I could actually get download speeds of 48k after using MTU Speed.
Be aware that if you are using any fax software and you change your modem settings you will more than likely have to reinstall your software or at least re-read the modem strings if that option is available, after applying any changes.
If you go to the link above, read through the readme file carefully and visit the links included in the Introduction paragraph, you will be able to learn all you want to about MTU....
Read the FAQ section too.
Before you change anything make sure you open a DOS window and type in scanreg /backup.
BTW Now I have a 56 K modem and whatever I do the maximum speed I seem to get is 51 K, country phone line is the cause.

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Just trying to give others a friendly hand.

[Nick Grana]

Everyone loves to tinker and I'm no exception so naturally I've tried little apps to
optimizing the MaxMTU & MaxMSS
and that guaranteed return to original settings if not happy. Guess what. Not happy and would not return to original settings. Made quite a few changes to some custom tweaks I had in the registry. Luckily I keep a HD removable backup, freshly backed, just for these occasions when my scanreg refused to get me back to where I wanted to be.
So short story, long, be careful and backup and if it sounds too good to be true.....
It usually is. C ya!

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"You have the right to remain silent. Anything you say will be misquoted, then used against you."

[carson]

Thanks All:
I appreciate the positives and negatives of tinkering around with this tweak.
Recently got a notice from my ISP that they will very soon offer DSL. So maybe I'll wait for that. (Nick scared me)