A CSMA-CD station entity manages a CSMA/CD controller. Wherever Phase IV DECnet manages a line, DECnet-Plus manages a station. Each station corresponds to a particular logical link control LLC, medium access control MAC, and physical attachment. The station name refers to the station managed by this command.
1 – character
STATION BUFFERS
Number of receive buffers reserved for the station. You can modify
this characteristic only when the entity is disabled.
2 – counters
Unless stated otherwise, counts include both normal and multicast traffic and
all protocol types, service access points SAPs, and protocol identifiers.
ALIGNMENT ERRORS
Number of times a received frame did not contain an integral number of
octets.
CARRIER CHECK FAILURES
Number of times the data link did not sense the receive carrier signal
or detected an error in the receive carrier signal during transmission
of a frame.
COLLISION DETECT CHECK FAILURES
Number of times the collision detect test signal was not sensed after
a transmission. If this count approximates the number of frames sent,
either the collision detect circuitry is not working correctly or the
test signal is not implemented.
DATA OVERRUNS
Number of times the hardware lost one or more consecutive, partially
complete, incoming frames because it could not keep up with the
incoming frame rate. Used in conjunction with pdus received, this
count provides a measure of hardware resource and bandwidth failures.
EXCESSIVE COLLISIONS
Number of times a transmission failed because the maximum allowable
number of retransmission attempts all culminated in collisions.
FRAME CHECK ERRORS
Number of times a received frame containing an integral number of
octets failed the frame check sequence FCS.
FRAME SIZE ERRORS
Number of times the user requested transmission of a frame outside the
range of valid frame sizes.
FRAMES TOO LONG
Number of times a received frame exceeded the maximum length allowed
by CSMA/CD medium access control.
INITIALLY DEFERRED PDUS SENT
Number of times a PDU was deferred by the station access algorithm on
the first attempt at transmission, but was then transmitted
successfully without collision. Used in conjunction with PDUs sent,
this count measures the rate of CSMA/CD contention with no collisions.
LATE COLLISIONS
Number of times a collision was detected after the allotted time for
collisions had expired.
MULTICAST OCTETS RECEIVED
Number of multicast data octets that were successfully received. The
count is the number of octets in the CSMA/CD user data field and does
not include MAC headers. Comparing this count to the octets received
count yields the gross percentage of bandwidth that was consumed over
time by multicast frames received by the local system.
MULTICAST OCTETS SENT
Number of multicast data octets that were successfully sent. The count
is the number of octets in the MAC user data field, including any
padding or length fields; it does not include MAC headers. Comparing
this count to the octets sent count yields the gross percentage of
bandwidth that was consumed over time by multicast frames
transmitted by the local system.
MULTICAST PDUS RECEIVED
Number of multicast PDUs that were successfully received. Comparing
this count to the pdus received count yields a gross percentage of
CSMA/CD usage for multicast PDUs received by this system.
MULTICAST PDUS SENT
Number of multicast PDUs that were successfully sent. Comparing this
count to the pdus sent count yields a gross percentage of CSMA/CD
usage for multicast PDUs sent by this system.
MULTIPLE COLLISIONS PDUS SENT
Number of times a PDU was successfully transmitted on the third or
later attempt by the station access algorithm after normal collisions
on previous attempts. Used in conjunction with pdus sent, this count
provides a measure of CSMA/CD media contention at a level where there
are collisions and the backoff algorithm no longer works efficiently.
OCTETS RECEIVED
Total number of MAC user data octets that were successfully received
from frames that passed address and protocol filtering for both
individual and multicast MAC addresses. The count is the number of
octets in the CSMA/CD user data field plus any padding, Ethernet
length fields, or LLC header fields; it does not include MAC
headers. Adding the octets received count to the protocol overhead
calculated from the pdus received count yields the amount of CSMA/CD
bandwidth consumed by frames received by the local system.
OCTETS SENT
Total number of user data octets that were successfully sent. The
count is the number of octets in the MAC user data field including any
padding or length fields; it does not include MAC headers. Adding the
octets sent count to the protocol overhead calculated from the pdus
sent count yields the amount of CSMA/CD bandwidth consumed over time
by frames sent by the local system.
PDUS RECEIVED
Total number of PDUs that passed address and protocol filtering and
were received without errors. The count provides a gross measurement
of incoming CSMA/CD usage by the local system; this information can be
used in conjunction with other counters to approximate the average
receive frame size or to determine the ratio of errors to successful
receives.
PDUS SENT
Total number of PDUs successfully sent. The count provides a gross
measurement of outgoing CSMA/CD usage by the local system; this
information can be used in conjunction with other counters to
approximate the average transmit frame size or to determine the ratio
of errors to successful transmissions.
RECEIVE DATA LENGTH ERRORS
Number of times a frame was received with a length field value that was
invalid for the number of octets actually received by medium access
control.
SEND DATA LENGTH ERRORS
Number of times the user requested transmission of an 802.3 frame with
a length field value that was not valid for the number of octets
actually passed.
SINGLE COLLISION PDUS SENT
Number of times a PDU was successfully transmitted on the second
attempt by the station access algorithm after a normal collision
occurred on the first attempt. Used in conjunction with pdus sent,
this count provides a measure of CSMA/CD media contention at a level
where there are collisions, but the backoff algorithm still works
efficiently.
STATION FAILURES
Number of times that the station self-testing procedures reported
failure.
UNAVAILABLE STATION BUFFERS
Number of times a complete, fully received PDU was discarded because
no station buffer was available. Used with pdus received, this count
provides a measure of receive problems related to the station buffer.
UNAVAILABLE USER BUFFERS
Number of times no user buffer was available for an incoming frame that
passed all filtering for the port. Used in conjunction with the pdus
received count, this counter can indicate the rate of user buffer
receive problems.
UNRECOGNIZED INDIVIDUAL DESTINATION PDUS
Number of times a received PDU with an individual destination MAC
address was discarded because there was no port with the correct
Ethernet protocol type, SNAP protocol identifier, or link logical
control SAP address enabled.
UNRECOGNIZED MULTICAST DESTINATION PDUS
Number of times a received PDU with a multicast destination MAC
address was discarded because there was no port with the correct
Ethernet protocol type, SNAP protocol identifier, or link logical
control SAP address enabled.
3 – status
ADDRESS FILTERS
All individual MAC addresses currently enabled by any of the ports on
the station.
COMMUNICATION PORT
DECnet-Plus device name for the station.
HARDWARE ADDRESS
Individual medium access control MAC address that was assigned during
manufacture of the communications hardware that is associated with the
station.
MAC ADDRESS
Current MAC address if any of the station. For more information about
the MAC address, refer to the enable command.
RECEIVE MODE
Current receive mode for the station. Some stations may not support
all modes.
NORMAL - The station receives only those frames individual and
multicast that meet the normal format, protocol, and
access control requirements.
ALL MULTICAST - The station receives all individual-addressed frames
that meet the normal format, protocol, and address
requirements, and all multicast-addressed frames
regardless of their format, protocol, and address
types.
PROMISCUOUS - The station receives all frames individual and
multicast regardless of format, Ethernet protocol
type, SNAP identifier, LLC SAP address, or MAC
address.
STATE
Operational state of the station.
OFF - The station is disabled.
ON - The station is enabled and available for use.
FAILED - Either an attempt to enable the station failed during
the self-test or the station was on and the data link
determined that the station would now fail the
self-test.
INITIALIZING - The station is currently being initialized and tested
by the data link.