If your network has systems that use longer IPG (the sum of ipg1 and ipg2), and if those systems seem to be slow when accessing the network, increase the values of ipg1 and ipg2 to match the longer IPGs of the other systems.

Defining an Additional Delay Before Transmitting a Packet

The adapter’s PFEX ASIC supports a programmable mode called local area network controller for Ethernet (LANCE) mode, which is set with the lance_mode parameter.

When a driver receives a packet with lance_mode enabled (the default), it adds an additional time delay 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 ipg0 delay helps to reduce collisions.

If lance_mode is disabled, the value of ipg0 is ignored and no additional delay is set. Only the delays set by ipg1 and ipg2 are used. Disable lance_mode if other systems keep sending a large number of back-to-back packets. Systems that have lance_mode enabled might not have enough time to transmit a large number of back-to-back packets on the network.

You can add an additional delay by setting the ipg0 parameter to a value from 0 to 31, which is the nibble time delay. Note that nibble time is the time it takes to transfer four bits on the link. If the link speed is 10 Mbps, nibble time is equal to 400 ns. If the link speed is 100 Mbps, the nibble time is equal to 40 ns.

For example, if the link speed is 10 Mbps, and you set ipg0 to 20, multiply 20 by 400 ns to get 8000 ns. If the link speed is 100 Mbps, and you set ipg0 to 30, you would multiply 30 by 40 ns to get 1200 ns.

TABLE B-4defines the lance_mode and ipg0 parameters.

TABLE B-4Parameters Defining lance_mode and ipg0

Parameter

Values

Description

 

 

 

 

lance_mode

0

0

= lance_mode disabled

 

1

1

= lance_mode enabled (default)

ipg0

0 to 31

Additional media byte time delay before

 

 

transmitting a packet (after receiving a

 

 

packet)

 

 

 

 

Note –The default value of ipg0 is 16, which is 6.4 microseconds for 10 Mbps and 0.64 microseconds for 100 Mbps.

Appendix B Configuring the Sun Quad FastEthernet Device Driver Parameters 61

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Sun Microsystems 6U manual Defining an Additional Delay Before Transmitting a Packet
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6U specifications

Sun Microsystems, a prominent player in the computing industry, made significant contributions to the development of high-performance hardware and software solutions. One of the notable products from the company is the 6U form factor, which refers to a specific standard for rack-mounted equipment. The 6U standard is particularly relevant in the context of server architecture, storage solutions, and other critical systems used in enterprise environments.

The 6U form factor typically stands at 10.5 inches in height, accommodating various configurations of hardware components while ensuring a compact footprint. This size makes it ideal for data centers and server rooms, where space is often at a premium. Sun Microsystems effectively utilized this form factor in its server lineup, catering to performance and density requirements.

A defining feature of Sun Microsystems' 6U models is their modular architecture. These servers support a range of powerful processors, including the UltraSPARC series, renowned for their high processing capabilities and energy efficiency. The use of the UltraSPARC architecture allows for robust multitasking and parallel processing, making these systems suitable for demanding applications such as database management and enterprise resource planning.

Moreover, Sun Microsystems integrated advanced memory technologies within their 6U designs. The servers support large amounts of RAM, utilizing technologies like ECC (Error-Correcting Code) memory to enhance data integrity. This is crucial for mission-critical applications where data loss can result in substantial operational impact.

In terms of connectivity, the 6U form factor features a variety of interfaces, including high-speed Ethernet ports, Fibre Channel connections, and USB ports. These options enable seamless integration into existing network infrastructures, facilitating efficient data transfer and storage management.

Storage solutions within the 6U framework include support for multiple RAID configurations and high-capacity disk drives. Sun Microsystems provided options for both SSD and traditional HDD storage, allowing organizations to tailor their systems to meet specific performance and capacity needs.

In addition to hardware characteristics, Sun Microsystems placed a strong emphasis on software compatibility. Their systems were designed to run a variety of operating systems, including Solaris, Linux, and Windows, thereby providing flexibility for enterprises to deploy their preferred software environments.

Overall, the 6U form factor from Sun Microsystems symbolizes the company's commitment to delivering high-performance, reliable, and scalable computing solutions. By combining innovative technology with practical design, Sun Microsystems created servers that met the diverse needs of businesses and paved the way for advancements in enterprise computing.
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