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Setting Parameters

25

4

Configuring TCP/IP for Maximum Performance

This section describes how to benchmark the TCP/IP throughput and how to
set the TCP/IP hiwater marks for best performance.

To benchmark the TCP/IP throughput

Use the

ndd

 command to configure the values of some of the TCP

parameters for maximum performance.

To set the TCP hiwater marks for best performance

Type the following

ndd

 commands:

Setting Parameters in the

/etc/system

 File

To configure the

hme

 driver parameters for all

SUNW,hme

 devices in the system

so that the parameter variables are always effective (even after rebooting the
system), enter the parameter variables in the

/etc/system

 file.  When you

reboot the system, the system reads the

/etc/system

 file and sets these

parameter variables in the

hme

 module in the operating system kernel.

Table 4-1 lists the variables you need to set in the

/etc/system

 file.

# ndd -set /dev/tcp tcp_xmit_hiwat 65535

# ndd -set /dev/tcp tcp_recv_hiwat 65535

# ndd -set /dev/tcp tcp_cwnd_max 65534

Table 4-1

Setting Variables in the

/etc/system

 File

Parameter

Variable

ipg1

hme_ipg1

ipg2

hme_ipg2

use_int_xcvr

hme_use_int_xcvr

pace_size

hme_pace_size

adv_autoneg_cap

hme_adv_autoneg_cap

Summary of Contents for Ethernet Device Driver none

Page 1: ...2550 Garcia Avenue Mountain View CA 94043 USA 415 960 1300 fax 415 969 9131 Sun Microsystems Computer Company PlatformNotes ThehmeFast Ethernet DeviceDriver Part No 802 5333 10 Revision A May 1996...

Page 2: ...Sun Microsystems the Sun logo Solaris NFS Online Backup Online DiskSuite Solstice DiskSuite X11 NeWS JumpStart Sun 4 SunSwift SunFastEthernet Enterprise and Ultra are trademarks or registered trademar...

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Page 4: ......

Page 5: ...s 3 2 The hme Device Driver 5 Hardware Overview 5 Operating Speeds and Modes 6 Auto Negotiation 6 Internal Transceiver 7 External Transceiver 7 3 Parameter Definitions 9 Driver Parameter Values and De...

Page 6: ...To specify the device instance for the ndd utility 20 Non Interactive and Interactive Modes 21 To modify a parameter value 21 To display the value of a parameter 22 To modify a parameter value in int...

Page 7: ...ng Parameters in the etc system File 25 To set the ipg1 to 10 and ipg2 to 5 when you reboot 26 Setting Parameters Using the hme conf File 27 To set ipg1 to 20 and ipg2 to 10 for the SUNW hme device in...

Page 8: ...viii Platform Notes The hme Fast Ethernet Device Driver May 1996...

Page 9: ...rv directory Chapter 2 describes the hme device driver and includes topics such as operating speeds and modes auto negotiation the internal transceiver and the external transceiver Chapter 3 describes...

Page 10: ...ographic conventions used in this book Table 1 1 Typographic Conventions Typeface or Symbol Meaning Example AaBbCc123 The names of commands files and directories on screen computer output Edit your lo...

Page 11: ...1 3 Table 1 2 Shell Prompts Shell Prompt C shell machine_name C shell superuser machine_name Bourne shell and Korn shell Bourne shell and Korn shell superuser Table 1 3 How to Order Sun Documents Coun...

Page 12: ...this document We are interested in improving our documentation and welcome your comments and suggestions If a card is not available you can also email or fax your comments to us Please include the pa...

Page 13: ...ver and the external transceiver for the hme device driver Note that the external transceiver is not present on the SunSwift SBus Adapter Hardware Overview The SUNW hme device provides 10BASE TX or 10...

Page 14: ...speeds and modes with the SUNW hme device 100 BASE T4 with external transceiver only 100 Mbps full duplex 100 Mbps half duplex 10 Mbps full duplex 10 Mbps half duplex Note An industry standard for fu...

Page 15: ...ing the auto negotiation protocol Internal Transceiver The internal transceiver is a feature supported by the driver and is capable of all the operating speeds and modes except the 100BASE T4 mode lis...

Page 16: ...t support auto negotiation the driver selects the highest priority mode supported by the transceiver You can also manually select the speed and mode of the link For example two transceivers might not...

Page 17: ...Defines the current status link_status Read only Defines the current status link_speed Read only Defines the current status link_mode Read only Defines the current status ipg1 Read and write Inter pac...

Page 18: ...dx_cap Read only Local transceiver capability of the hardware 10hdx_cap Read only Local transceiver capability of the hardware lp_autoneg_cap Read only Link partner auto negotiation capability lp_100T...

Page 19: ...peed is 100 Mbps the total IPG is 0 96 microseconds Table 3 3 lists the default values and allowable values for the inter packet gap IPG parameters ipg1 and ipg2 Table 3 2 Read Only Parameters Definin...

Page 20: ...he ipg0 parameter before transmitting the packet This delay set by the ipg0 parameter is in addition to the delay set by the ipg1 and ipg2 parameters The additional delay set by ipg0 helps to reduce c...

Page 21: ...t after receiving a packet Table 3 5 Operational Mode Parameters Parameter Values Description adv_autoneg_cap 0 1 Local transceiver capability advertised by the hardware Forced mode Auto negotiation d...

Page 22: ...to use_int_xcvr 1 the driver selects the internal transceiver even if the external transceiver is connected 1 The priority in descending order for these parameters is adv_100T4_cap adv_100fdx_cap adv_...

Page 23: ...3 6 Back to back Packet Transmission Capability Parameter Values Description pace_size 1 to 255 0 Number of back to back packets transmitted at one time No limit to the number of back to back packets...

Page 24: ...lities 100hdx_cap 0 1 Local transceiver capability of the hardware initialized at startup Not 100Mbit sec half duplex capable 100Mbit sec half duplex capable 10fdx_cap 0 1 Local transceiver capability...

Page 25: ...g_cap is 1 then the speed and mode information is displayed when you use auto negotiation and get the link partner capabilities lp_100hdx_cap 0 1 No 100Mbit sec half duplex transmission 100Mbit sec ha...

Page 26: ...18 Platform Notes The hme Fast Ethernet Device Driver May 1996 3...

Page 27: ...tc system file and sets the parameter values in that file To set a particular parameter for a device in the system set the parameter in the hme conf file in the kernel drv directory The parameters set...

Page 28: ...ng Parameters Using ndd Use the ndd utility to configure parameters that are valid until you reboot the system The ndd utility supports any networking driver which implements the Data Link Provider In...

Page 29: ...tility In interactive mode you can use the utility to get or set more than one parameter value Refer to the ndd 1M man page for more information Using the ndd Utility in Non Interactive Mode This sect...

Page 30: ...s the value associated with the specified parameter and prints it Using the ndd Utility in Interactive Mode To modify a parameter value in interactive mode Specify ndd hme as shown below The ndd utili...

Page 31: ...ce_size read and write adv_autoneg_cap read and write adv_100T4_cap read and write adv_100fdx_cap read and write adv_100hdx_cap read and write adv_10fdx_cap read and write adv_10hdx_cap read and write...

Page 32: ...r capabilities advertised by the hardware to forced mode 0 which is not capable of auto negotiation adv_autoneg_cap 0 Use the ndd utility as described in Using the ndd Utility in Interactive Mode on p...

Page 33: ...r all SUNW hme devices in the system so that the parameter variables are always effective even after rebooting the system enter the parameter variables in the etc system file When you reboot the syste...

Page 34: ...following lines to the etc system file 3 Save the etc system file 4 Save all files and exit all programs Exit the windowing system 5 Reboot the system by typing init 6 at the prompt The system is halt...

Page 35: ...set ipg1 to 20 and ipg2 to 10 for the SUNW hme device in SBus slot 0xe 1 Invoke the prtconf v command and pipe the output to the more command prtconf v more or redirect the output of the command to a...

Page 36: ...d sizes Precede each size with 0x and leading zeros as indicated in the following screen Set ipg1 and ipg2 These parameters are set to 20 and 10 respectively in this example Type a semicolon after the...

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