Novell NETWARE 6, Руководство пользователя

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148
Internetwork Packet Exchange
Internetwork Packet Exchange
103-000176-001
August 29, 2001
Novell Confidential
Manual 99a
38
July 17, 2001
Cause 2 —Application relies on ticks to retransmit its packets. This should
not happen with the routing software, but it is possible that some other
manufacturer's router does not comply with the ticks value.
If this is the case, increase the cost of the routing software to match the value
of the router in question. This procedure should not affect other paths much,
but it should help to stop the application from retransmitting packets.
Cause 3 —Router is in an NLSP area and you have routers with load sharing
enabled. This causes the application to retransmit packets needlessly.
If this is the case, turn off load sharing to see whether the situation improves.
Cause 4 —Link speed is too slow. You might be choosing the optimal path,
but throughput is still not adequate.
Š If you have a Novell router and the protocol is windowed, you might want
to enable the IPX Header Compression option or experiment with PPP
data compression, if it is being used. However, the application might
require more bandwidth than you have available.
Š Make sure that the problem is not caused by latency. Compression adds
latency, which can slow down protocols that do not have windowing, such
as the Sequenced Packet Exchange
TM
(SPX
TM
) protocol. Also, older
versions of the NetWare shells do not have windowing. If you experiment
with the Packet Burst
TM
protocol, you might be able to reduce latency and
increase throughput.
Š If this is an X.25 problem, you might be able to remove some of the
latency by increasing the X.25 window size, the physical frame size, or
both.
Š If the previous suggestions do not work, change the type of line that you
have. Some kinds of frame relay lines have relatively low latency, as do
leased lines. X.25 and other WAN technologies sometimes have high
latency. If an X.25 problem exists, you can remove some of the latency
by increasing the X.25 window size, the physical frame size, or both.
Over slow PPP lines, increasing the frame size continually can hurt
performance. Because this can cause packets to be retransmitted, it can
take a long time to transmit a single frame across the link.
Cause 5 —Malfunctioning routers in the end-to-end path or a link that is
causing problems in the end-to-end path.
Determine the routers in the end-to-end path and check each router and link
for abnormal behavior.