TCP sessions limit

[George Valkov]

Can I limit (restrict) the maximum number of TCP sessions for an XP system?

Here is the problem:
I share my internet with a friend. His PC has more that 30 active TCP
sessions and even when I restrict his speed to 45% of the Internet speed, I
can hardly reach 10%. When he is offline I reach the total 100% of internet
speed.

ADSL modem (512 down/ 128 up) --> router --> PC1 and PC2

I'm looking for a registry setting or policy restriction on PC2, to prevent
him from opening more that 10 TCP sessions. This is not supported by the
router.


Thank You for any help!

 

[Dan Abernathy]

The usual warning about backing up the Windows Registry before doing
anything
applies here.

I'll add another warning about changing settings on your friend's computer,
Have you asked for his permission?

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters

Add a new DWORD value named TcpNumConnections. Set the value to the maximum
number of TCP connections you want. It's easier to
click the Decimal radio button and enter the number, it'll automatically
be converted to Hex for you, e.g. if you're setting the maximum to 15 the
value will change to 0x0000000f (15).

TcpNumConnections
Key: Tcpip\Parameters
Value Type: REG_DWORD - Number
Valid Range: 0 - 0xfffffe
Default: 0xfffffe
Description: This parameter limits the maximum number of connections that
TCP can have open at the same time.

More information can be found in KB314053:
http://support.microsoft.com/default.aspx?kbid=314053

 

[George Valkov]

Thank You for the help!
Me and my friend will test the configuration tomorrow (it's gettings late),
and post back our thesting experience. My frined is pretty unexperienced but
I'm trying to teach him, whatever I can.

I use regedit frequently, so there won't be any problems, but thanks for the
advice!


George Valkov

 

[Vincent Xu [MSFT]]

Hi George ,

Thanks for your posting.

It appears that Dan provided the information you needed. I'm glad to see
that. Please feel free to post back the results or if you still have
concerns about this issue. We are glad to provide assistance.

Have a good day!


Best regards,

Vincent Xu
Microsoft Online Partner Support

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--------------------

 

[George Valkov]

So far my friend has no problems with this new configuration:
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters]
TcpNumConnections = 0xF (15) as REG_DWORD

On the other hand my internet connection has much better performance.

I expected my friend to have connectivity problems and also to be
unreachable when he reaches the maximum number of connections. So I told him
in such case to simply stop the application that makes many TCP sessions and
continue his work. He had no problems so far, but this is a configuration
that needs more time to test, so we'll examine it and I may post more
results in a few days or a week.

I had no problems connecting to his PC via SMB and also...
Telnet - to monitor his connections:

netstat -n
netstat -bn
I can use this one (-:
netstat -bn |msg 0
to send the results as a message to him

 

[Vincent Xu [MSFT]]

Hi George,

Thanks for your reply.

I totaly understand your situation. Feel free to post back if the problem
re-occur.

Have a good day!


Best regards,

Vincent Xu
Microsoft Online Partner Support

======================================================
Get Secure! - www.microsoft.com/security
======================================================
When responding to posts, please "Reply to Group" via your newsreader so
that others
may learn and benefit from this issue.
======================================================
This posting is provided "AS IS" with no warranties,and confers no rights.
======================================================



--------------------

From: "George Valkov" <[email protected]>
References: <[email protected]>

<[email protected]>

Subject: Re: TCP sessions limit
Date: Wed, 6 Sep 2006 14:41:46 +0300
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So far my friend has no problems with this new configuration:
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters]
TcpNumConnections = 0xF (15) as REG_DWORD

On the other hand my internet connection has much better performance.

I expected my friend to have connectivity problems and also to be
unreachable when he reaches the maximum number of connections. So I told him
in such case to simply stop the application that makes many TCP sessions and
continue his work. He had no problems so far, but this is a configuration
that needs more time to test, so we'll examine it and I may post more
results in a few days or a week.

I had no problems connecting to his PC via SMB and also...
Telnet - to monitor his connections:

netstat -n
netstat -bn
I can use this one (-:
netstat -bn |msg 0
to send the results as a message to him