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Did the atmtest diagnostic fail – Sun Microsystems 3U User Manual

Page 131

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Appendix D

Troubleshooting and SunATM Error Messages

109

Do you want to increase system performance by adjusting TCP/IP
parameters?

TCP/IP performance over an ATM network can be poor unless you carefully
configure your network. Poor performance usually occurs because the TCP/IP
packets are segmented into cells for transmission by the ATM software. Therefore, a
loss of a single cell can cause the loss of an entire TCP/IP packet which can lead to
retransmissions that congest the network. When it detects congestion, the
destination system reduces the transmission rate, which significantly reduces the
network performance.

You can achieve better network performance from the SunATM adapter and
software by adjusting your application’s socket buffer size to 48 Kbytes. Refer to the
application’s documentation for instructions on how to set the socket buffer size.

Are you trying to mount a diskless, dataless, or autoclient system?

The SunATM adapters do not currently support diskless, dataless, or autoclient
systems. The

root

filesystem must be local for the SunATM adapter to operate.

Did the

atmtest

diagnostic fail?

If the bandwidth or outstanding packets value is set too high on your system, the
SunVTS

atmtest

diagnostic can fail, giving an error similar to the following:

To correct this error, reduce the bandwidth or the number of outstanding packets in
the SunVTS

atmtest

.

SUNWvts.atmtest.4000 09/17/98 17:33:10 atmtest ba0

WARNING: “VC30 dropped pkt, seq: exp=41, obs=43; len: exp=1747,

obs=6022”