User's Manual

Technical Description & Configuration Guide Performance and Alarm Management
LigoWave Page 73
Modem state – shows if the modem is operating correctly;
Clear statistics – 
Truncated frames  number of truncated received frames;
Long events  frames having byte count greater than MAXIMUM FRAME SIZE parameter (1518,
1536 or 1916 bytes);
Vlan tags detected – VLAN tagged frames;
Unsup. opcodes  frames recognized as control frames but contained an Unknown Opcode;
Pause frames  frames received are control frames with valid PAUSE opcodes;
Control frames  frames received as control frames;
Dribble nibbles – indicates that following the end of the packet additional 1 to 7 bits are received. A
single nibble, named the dribble nibble, is formed but not sent to the system;
Broadcasts  packets, which destination address contained broadcast address;
Multicasts  packets, which destination address contained multicast address;
Dones  reception of packets successfully completed;
Out of range errors – frame Type/Length field larger than 1518 (Type Field) bytes;
Length check errors  frame length field in the packet does not match the actual data byte length and
is not a Type Field;
CRC errors  frame CRC do not match the internally generated CRC;
Code errors  one or more nibbles are signalled as errors during reception of the packet;
False carrier errors  indicates that following the last received statistics vector, a false carrier was
detected, noted and reported with this the next receive statistics. The false carrier is not associated
with this packet. False carrier is activated on the receive channel that does not result in a packet
receive attempt being made;
Rx Dv event  indicates that the last receive event seen is too short to be a valid packet;
Prev. pkt dropped  indicates that since the last RSV, a packet is dropped (i.e. interframe gap too
small);
Byte counter  total number of bytes received on the wire, not counting collided bytes;
FCS errors – number of generic framing procedure (GFP) frames with CRC errors received by the de-
encapsulation block;
CHEC errors  number of generic framing procedure (GFP) frames with CHEC errors received by the
de-encapsulation block;
Dropped frames  number of generic framing procedure (GFP) frames that were dropped in the de-
encapsulation block;
Delineation errors  
Vlan tags – number of VLAN tagged packets, 32-bit counter;
Backpres. events  carrier-sense-method backpressure was previously applied;
Pause frames  frames transmitted are control frames with a valid PAUSE opcodes;
Control frames  frames transmitted are control frames;
Wire byte counter – total number of bytes transmitted on the wire, including all bytes from collided
attempts;
Underruns  underruns occur during frame transmission;
Giants  frames having byte count greater than the MAXIMUM FRAME SIZE parameter (1516, 1536
or 1916 bytes);
Late collisions  Collisions occurred beyond the collision window (512 bit times);
Max collisions – packets aborted after number of collisions exceeded the RETRANSMISSION
MAXIMUM parameter;