NS3000/iX Operations and Maintenance Reference Manual (36922-90039)

186 AppendixA
LINKCONTROL Command
NS 3000/iX LAN Link Statistics
Transmits 16 collisions. The Transmits 16 collisions field indicates
the number of times a frame or frames were not transmitted because 16
consecutive collisions occurred. This commonly occurs in the protocol
during periods of high network utilization. If your node is experiencing
continuous retry errors, the problem is most likely that a terminator
has been removed from the cable. Other possible causes include the
following:
• There is an opening in the cable.
• If ThinLAN cable is used, the AUI may be disconnected.
• The LAN cable may shorted.
Whole byte errors. The Whole byte errors field is the number of
frames received that were not an integer multiple number of bytes long.
This occurs when an entire byte is not transmitted. This usually also
causes the CRC error to be set.
Transmits late collision. This field indicates that a frame was active
in the network for a longer time than is permitted by the protocol. The
IEEE 802.3 protocol expects each frame to be transmitted within one
slot time (the expected time for a 512 bit packet to traverse the entire
network). The slot time exceeds the amount of time a single frame
should need to traverse the entire network.
A value in this field indicates that a network problem caused a late
collision. A late collision is one in which the collision occurs after one
slot time has passed and another node, sensing that the network is
inactive, begins to transmit a frame. Late collisions are caused by one of
the following:
• Broken LAN cards in the network.
• A network that is too long.
A network can be made too long by installing too many repeaters
between nodes. HP MAUs inform the LAN card of collisions after the
512 bit timer expires even though IEEE 802.3 standards do not require
the MAU to monitor the link beyond that time. No attempt is made to
retransmit a frame after a late collision.
Size range errors. The Size range errors field indicates the number of
frames received that are not within the allowable size range. The
allowable size range is 64–1518 bytes long. Unless the save bad frames
bit is set on the LAN hardware card, the LAN hardware card throws
these packets out.
802 chip restarts. The 802 chip restarts field was initially used to
count the number of times that a specific version of the LAN chip locked
up. This problem was remedied by a new version of that chip, however,
this field still returns a value when one of the following events occurs: