A CSMA-CD Port entity represents an access point to the service offered by the CSMA-CD module. A client transmits and receives data through a port. Ports are created and deleted by client use of open and close service interface procedures.
1 – counters
Unless stated otherwise, counts include both normal and multicast traffic and all protocol types, service access points SAPs, and protocol identifiers. MULTICAST OCTETS RECEIVED Number of multicast data octets that were successfully received and made available to the port user. The count is the number of octets in the CSMA/CD user data field and does not include MAC medium access control, a sublayer of the CSMA/CD Data Link layer headers. Comparing this count to the octets received count yields the gross percentage of bandwidth that was consumed over time by multicast PDUs received by the port. MULTICAST OCTETS SENT Number of multicast data octets that were successfully sent through the port. 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 PDUs transmitted by the port. MULTICAST PDUS RECEIVED Number of multicast PDUs that were successfully received and made available to the port user. Counted PDUs passed address and protocol filtering and were received without errors. Comparing this count to the PDUs received count yields a gross percentage of CSMA/CD usage for multicast pdus received by this port. MULTICAST PDUS SENT Number of multicast PDUs that were successfully sent through the port. Comparing this count to the PDUs sent count yields a gross percentage of CSMA/CD usage for multicast PDUs sent by this port. OCTETS RECEIVED Total number of MAC user data octets that were successfully received and made available to the port user. Counted frames passed address and protocol filtering for both individual and multicast MAC addresses and were received without errors. The count is the number of octets in the CSMA/CD user data field plus any padding, Ethernet length fields, or logical link control 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 port. OCTETS SENT Total number of user data octets that were successfully sent through the port. 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 port. PDUS RECEIVED Total number of PDUs that were successfully received and made available to the port user. Counted PDUs passed address and protocol filtering and were received without errors. The count provides a gross measurement of incoming CSMA/CD usage by the port. PDUS SENT Total number of PDUs that were successfully sent through the port. The count provides a gross measurement of outgoing CSMA/CD usage by the port. UNAVAILABLE USER BUFFERS Number of times that no user buffer was available at the port 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.
2 – status
CLIENT Name specified by the data link user when the port was opened. ETHERNET PROTOCOL TYPES Set of Ethernet protocol types that are currently recognized for this port. LENGTH PRESENT The data link adds a length field on transmit frames, and assumes the presence of a length field and attempts to remove it on received Ethernet frames. When false, the data link does not add and remove length fields. This attribute is irrelevant for ISO 8802-3 formatted frames, which always have a length field. TRUE - The data link adds and removes length fields. FALSE - The data link does not add and remove length fields. LLC SAP ADDRESSES Set of individual and group logical link control LLC service access point SAP addresses that are currently recognized for this port. LLC SERVICE Type of LLC logical link control PDU processing that is required on the port as defined by the user when the port was opened. CLASS 1 - The data link provides class 1, type 1 service. USER-SUPPLIED - The user is responsible for handling the LLC protocol. MAC ADDRESSES Set of individual and multicast MAC medium access control addresses that are currently recognized for this port. RECEIVE MODE Type of receive mode that is currently enabled for the port. NORMAL - The port receives only those frames that meet the normal address and protocol filtering requirements requested by the user. PROMISCUOUS - The port receives all frames regardless of format and MAC address. SNAP PROTOCOL IDENTIFIERS Set of subnetwork access protocol SNAP identifiers that are currently recognized for this port. STATION Name of the station associated with this port as specified by the user when the port was opened.