réglage automatique du MTU

[rojni]

Voilà ce que je viens de trouver.

Vous pouvez configurer ce paramètre pour qu'il calcule le MTU entre votre PC et la machine distante, en général votre fournisseur d'accès.

Cela évite la fragmentation de l'information et peut rendre plus performante votre connexion internet.

 

Lancer l'EDITEUR de REGISTRE.

 

- HKEY_LOCAL_MACHINE

    SYSTEM

      CurrentControlSet

        Services

          Tcpip

            Parameters

 

- Céer ou modifier la valeur Dword "EnablePMTUDiscovery" et lui donner la valeur "1".

 

SOURCE : Top Astuces

URL : http://www.topastuces.com/win_xp/wxp48.htm

 

J'ai pas encore testé. Qu'est ce que vous en pensez?

[rojni]

Je viens de tester, et d'après les quelques tests en ligne que je viens de faire, il me semble qu'il y a un léger mieux...

au suivant...

Modifié le 24 avril 2003 par rojni

[Greywolf]

tiens ici tu trouveras tout plein de settings de la branche TCP/IP parameters pour 2K/XP (y'en a d'autre sur le site):

http://www.speedguide.net/read_articles.php?id=157

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters

 

TCPWindowSize

 

The value of TCP Window in the Windows 2000 Registry is DWORD, representing number of bytes, with range from 0 to 2^30. The recommended values (in red) optimize TCP for any high speed Internet connection and work best in most cases, however if you'd like to use a custom value follow these guidelines:

 

For best results, the TCPWindow should be a multiple of MSS (Maximum Segment Size). MSS is generally MTU - 40, where MTU (Maximum Transmission Unit) is the largest packet size that can be transmitted. MTU is usually 1500 (1492 for PPPoE connections). To determine the MTU value of your ISP, check out the Advanced Registry Editing section of our site.

 

There are three places in the Windows 2000 Registry where you can add the TCP Window parameter.

 

HKLM/SYSTEM\CurrentControlSet\Services\Tcpip\Parameters

GlobalMaxTcpWindowSize="256960" (DWORD, number of bytes) Valid range is from MSS to 2^30. Add the value as a decimal. Note: For best results RWIN has to be a multiple of MSS lower than 65535 times a scale factor that's a power of 2, i.e. 44 x 1460 = 64240 x 2^2 = 256960. If you choose to use a RWIN lower than 65535, you can simply make it multiple of MSS and turn scaling off (Tcp1323Opts=0)

 

HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters

TcpWindowSize="256960" (DWORD, number of bytes) Valid range is from MSS to 2^30. Add the value as a decimal. TcpWindowSize can also exist under TcpipParametersInterface - if added at this location, it overrides the global setting for this particular . Note (10/20/00): Seems MS has found another bug in Windows 2000, the TCPWindowSize should be configured with the global setting (GlobalMaxTcpWindowsSize) rather than this one - Q263088

 

Note: For best results RWIN has to be a multiple of MSS lower than 65535 times a scale factor that's a power of 2, i.e. 44 x 1460 = 64240 x 2^2 = 256960. If you choose to use a RWIN lower than 65535, you can simply make it multiple of MSS and turn scaling off (Tcp1323Opts=0)

 

Tcp1323Opts

 

Tcp1323Opts is a necessary setting in order to enable Large TCPWindow support as described in RFC 1323. Without this parameter, the TCPWindow is limited to 64K.

 

HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters

Tcp1323Opts="1" (DWORD, recommended setting is 1. The possible settings are 0 - Disable RFC 1323 options, 1 - Window scaling but no Timestamp options, 3 - Window scaling and Time stamp options.)

 

Note: Tcp1323Opts="3" might help in some cases where there is increased packet loss, however generally you'll achieve better throughput with Tcp1323Opts="1", since Timestamps add 12 bytes to the header of each packet.

 

DefaultTTL

 

DefaultTTL determines the time in seconds and the number of hops a packet lives. While it does not directly affect speed, a larger value increases the amount of time it takes for a packet to be considered lost, discarded and retransmitted. A value that's too small can cause packets to distant servers not to reach their destination at all.

 

HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters

DefaultTTL="64" (DWORD, recommended setting is 64. Other settings that are widely used are 128 and 32)

 

EnablePMTUDiscovery

 

When set to 1 (True), TCP attempts to discover MTU automatically over the path to a remote host. Setting this parameter to 0 causes MTU to default to 576 which reduces overall performance over high speed connections. Note that this setting is different than our Windows 9x recommendation.

 

HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters

EnablePMTUDiscovery="1" (DWORD - boolean, valid settings are 0-->False and 1-->True. Many connections perform better with this entry at 1, however, if you prefer to set your upstream to send fixed 1500 packets, you might want to use 0 instead). When set at 1, establishing connections and initial transfer speed might slow down a bit, however you will get better throughput if somewhere in the path large packets need to be fragmented.

 

EnablePMTUBHDetect

 

Setting this parameter to 1 (True) enables "black hole" routers to be detected, however it also increases the maximum number of retransmissions for a given segment. In most cases you'd want to keep BHDetect to 0 (False).

 

HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters

EnablePMTUBHDetect="0" (DWORD - boolean, valid settings are 0-->False and 1-->True. Recommended setting is 0)

 

SackOpts

 

This parameter controls whether or not SACK (Selective Acknowledgement) support is enabled, as specified in RFC 2018. SACK is especially important for connections using large TCP Window sizes.

 

HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters

SackOpts="1" (DWORD - boolean, recommended setting is 1. Possible settings are 0 - No Sack options or 1 - Sack Option enabled).

 

TcpMaxDupAcks

 

This parameter determines the number of duplicate ACKs that must be received for the same sequence number of sent data before "fast retransmit" is triggered to resend the segment that has been dropped in transit.

 

HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters

TcpMaxDupAcks="2" (DWORD - range 1-3, recommended setting is 2).

[Yann]

Je suis en train de paufiner une astuce de réglage MTU... si vous avez d'autre infos, je suis prenneur

[Greywolf]

les mêmes pour Win9X/ME

http://www.speedguide.net/read_articles.php?id=119

Registry Key:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\VxD\MSTCP

Value Name: DefaultRcvWindow

Value Type: String Value

Value Data: 64240

Details: has to be a multiple of MSS for best results, i.e. (MaxMTU-40) x number... Best settings to try with MSS=1460 are 64240, 46720 and 23360, in that order

 

Registry Key: HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Class\NetTrans<!--POST BOX-->00n

(Where "000n" is your TCP / IP protocol. It contains "TCP / IP" assigned to the "DriverDesc" Value)

Value Name: MaxMTU

Value Type: String Value

Value Data: 1500

Details: If you're using DSL and your ISP has implemented PPPoE, you should set MaxMTU to 1492 or less.

 

Registry Key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\VxD\MSTCP

Value Name: DefaultTTL

Value Type: String Value

Value Data: 64

Details: range 1-255, use any number between 32 and 128

 

Registry Key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\VxD\MSTCP

Value Name: PMTUDiscovery

Value Type: String Value

Value Data: 1

Details: Boolean value, 0-false or 1-true. Many connections perform better with this entry at 1, however, if you prefer to set your upstream to send fixed 1500 packets, you might want to use 0 instead. When set at 1, establishing connections and initial transfer speed might slow down a bit, however you will get better throughput if somewhere in the path large packets need to be fragmented.

 

Registry Key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\VxD\MSTCP

Value Name: PMTUBlackHoleDetect

Value Type: String Value

Value Data: 0

Details: zero for optimal performance

 

Registry Key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\VxD\MSTCP

Value Name: Tcp1323Opts

Value Type: String Value

Value Data: 1

Details:

The possible settings are 0 - No Windowscaling and Timestamp Options, 1 - Window scaling but no Timestamp options, 3 - Window scaling and Time stamp options. The value is documented in RFC 1323. According to Microsoft, Tcp1323Opts should be a DWORD, rather than a string value, however seems that the documentation is incorrect and a string value is necessary to enable large RWIN suppert.

 

Registry Key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\VxD\MSTCP

Value Name: SackOpts

Value Type: String Value

Value Data: 1

Details:

Possible settings are 0 - No Sack options or 1 - Sack Option enabled. Selective Acknowledgements are documented in RFC 2018

 

Registry Key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\VXD\MSTCP\Parameters

Value Name: MaxDupAcks

Value Type: DWORD Value

Value Data: 2

Details:

taking integer values from 2 to N

[Y@kuz@]

j'utilises depuis un bail le MTUDiscovery=1 ainsi que tous les autres paramètres cités , en gros suffirait de faire un snapshot de la bdr, de lancer tweakmaster , optimiser , rebooter refaire un snpashot de la bdr en la comparant à la première dans un > .txt , le renommer en .reg et vous avez la super astuce opti dsl , cable

 

bonne soirée