The IP protocol stack is
configured to maximize performance on all supported
network adapters. If desired, you can further adjust performance
parameters for each network interface using the
ifconfig(ADMN)
command as described in
``Using ifconfig to change parameters for a network card''.
This command allows you to adjust:
The send and receive TCP window for an interface.
These windows are used by two communicating systems to negotiate
the amount of data that can be sent before an acknowledgement is
required. The default values of these windows are set to optimize
performance on a local area network (LAN).
If you are using a high bandwidth, and high latency connection
such as a satellite link, increase the values of these parameters to
increase
throughput
on the link.
The maximum value that you can set is 64KB.
The maximum segment size (MSS) rounding parameter.
This is a boolean value; if set to 1, TCP negotiates
the largest segment size that can be transmitted in
the maximum transmission unit of the physical network. This is
also referred to as using full frames.
If set to 0, the MSS is rounded down to the nearest power
of 2. For Ethernet, this corresponds to 1KB.
With modern Ethernet hardware, you should use full frames
to maximize the amount of data per Ethernet frame.
On older Ethernet cards with small buffers and narrow data paths,
rounding down should be selected to
enable the data in the Ethernet
frame to be moved into the card's buffer more efficiently.
Token Ring networks have a much larger MTU than Ethernet;
full frames should always be used.
One-packet mode.
This should be set for older network adapters whose small
buffers cannot handle back-to-back streams of packets.
Time-to-live.
If it is known that a substantial number of network hops will be
necessary for a packet to reach its destination, increase this
parameter.
There is intermittent loss of connection due to the network being
incorrectly configured physically. See
``Testing network connectivity''
for ways of testing this.
Other performance considerations for TCP/IP include:
Altering the functionality of the domain name server to
decrease system load, or to balance the load between the network
and the local machine as described in
``Configuring DNS name service for performance''.