ip_multidata_outbound

Description

Enables the network stack to send more than one packet at one time to the network device driver during transmission.

Enabling this parameter reduces the per-packet processing costs by improving host CPU utilization, network throughput, or both.

This parameter now controls the use of multidata transmit (MDT) for transmitting IP fragments. For example, when sending out a UDP payload larger than the link MTU. When this tunable is enabled, IP fragments of a particular upper-level protocol, such as UDP, are delivered in batches to the network device driver. Disabling this feature results in both TCP and IP fragmentation logic in the network stack to revert back to sending one packet at a time to the driver.

The MDT feature is only effective for device drivers that support this feature.

See also tcp_mdt_max_pbufs.

Default

1 (Enabled)

Range

0 (disabled) or 1 (enabled)

Dynamic?

Yes

When to Change

If you do not want this parameter enabled for debugging purposes or for any other reasons, disable it.

Commitment Level

Unstable

Change History

For information, see ip_multidata_outbound (Solaris 10 Release).