Cambium Networks PMP 450 AP, Configuration Manual

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Chapter 3: Operation System statistics
Page
3-46
CRCError This field displays how many CRC errors occurred on the Ethernet controller.
RcvFifoNoBuf This field displays the number of times no FIFO buffer space was able to be
allocated.
Note:
PMP 450 AP running in Gigabit Ethernet Mode displays
error “RcfFifoNoBuf” which indicates packet loss.
For 450 AP platforms, if ethernet auto-negotation is set to
Gigabit, then it is a known limitation that “RcfFifoNoBuf”
error will be seen. This issue is not seen if autonegotation
is set to 100Mbps or lower, and the issue is not seen on
450i or 450m AP's.
RxOverrun This field displays how many receiver overrun errors occurred on the
Ethernet controller.
Late Collision This field displays how many late collisions occurred on the Ethernet
controller. A normal collision occurs during the first 512 bits of the frame
transmission. A collision that occurs after the first 512 bits is considered a
late collision.
Caution
A late collision is a serious network problem because the
frame being transmitted is discarded. A late collision is most
commonly caused by a mismatch between duplex
configurations at the ends of a link segment.
RetransLimitExp This field displays how many times the retransmit limit has expired.
TxUnderrun This field displays how many transmission-underrun errors occurred on the
Ethernet controller.
CarSenseLost This field displays how many carrier sense lost errors occurred on the
Ethernet controller.
No Carrier This field displays how many no carrier errors occurred on the Ethernet
controller.