An OSI transport port entity represents one end of a transport connection and maintains status information about that connection. Although the connectionless transport protocol does not create transport connections, ports are still used to maintain status information.
1 – Counters
DUPLICATE PDUS RECEIVED
Total number of all types of detected duplicate TPDUs received from the
remote NSAP. This attribute applies only to COTS.
FAILED CHECKSUM
Number of checksum failure events detected.
PDUS RECEIVED
Total number of all types of TPDUs received from the remote NSAP
excluding detected duplicates.
PDUS SENT
Total number of all types of TPDUs sent to the remote NSAP excluding
retransmissions.
RETRANSMITTED PDUS
Total number of all types of retransmitted TPDUs sent to the remote
NSAP.
TOTAL OCTETS RECEIVED
Total number of octets of all types of TPDUs received from the remote
NSAP, regardless of their disposition. This count includes detected
duplicates.
TOTAL OCTETS SENT
Total number of octets of all types of TPDUs sent to the remote NSAP,
including retransmissions.
USER OCTETS RECEIVED
Total number of user data octets received from the remote NSAP,
including normal, expedited, connect, accept, and disconnect data. This
count does not include duplicates such as data retransmitted by the
remote NSAP.
USER OCTETS SENT
Total number of user data octets sent to the remote NSAP, including
normal, expedited, connect, accept, and disconnect data. This count
does not include data retransmitted by the local NSAP.
USER PDUS RECEIVED
Total number of PDUs containing user data received from the remote
NSAP, including normal, expedited, connect, accept, and disconnect
data. This count does not include duplicates such as TPDUs
retransmitted by the remote NSAP.
USER PDUS SENT
Total number of TPDUs containing user data sent to the remote NSAP,
including normal, expedited, connect, accept, and disconnect data. This
count does not include retransmitted TPDUs.
2 – status
ACKNOWLEDGMENT DELAY TIME
Maximum amount of time, in seconds, that an AK TPDU is to be withheld.
This attribute applies to protocol class 4 only.
CHECKSUMS
Indicates whether checksums are in use on the transport connection.
This attribute is supported only for class 4 protocol.
CLIENT
Name designated by the port user when the port was opened. If DNA
session control is being used, this is the name of the session control
port being used.
CONS TEMPLATE
When operating over the CONS, the name of the X.25 Access module's
template specified when establishing the underlying network connection.
CR TIMEOUT
Amount of time, in seconds, to wait for a response to a CR TPDU before
assuming that the remote transport service provider will not respond.
This attribute is valid for protocol classes 0 and 2 only.
DIRECTION
Indicates whether the port is open to initiate an outgoing connection,
to receive an incoming connection, or is listening for incoming
connection requests.
INCOMING - Transport connection initiated by remote transport service.
LISTENING - Listening for incoming connection requests.
OUTGOING - Transport connection initiated by this transport service.
UNKNOWN - Port direction is not known.
ER TIMEOUT
Amount of time, in seconds, to wait for a response to an ER TPDU
before disconnecting the network connection. This attribute is valid
for protocol classes 0 and 2 only.
EXPEDITED DATA
Indicates whether the expedited data option is in use for the transport
connection. This attribute is supported only for class 2 and class 4
protocols.
EXTENDED FORMAT
Indicates whether the use of extended formats should be negotiated for
a transport connection which operates the class 2 or 4 protocol.
INACTIVITY TIME
Time, in seconds, being used for the inactivity timer. This value is
the product of multiplying the keepalive time by the inactivity
factor architectural constant = 4. This attribute is valid for
protocol class 4 only.
INITIAL RETRANSMIT TIME
Time, in seconds, used for the retransmission timer when sending the
first TPDU on the transport connection. The value of this attribute
is derived from the template used when the port was initialized. This
attribute applies to COTS only.
KEEPALIVE TIME
Time, in seconds, being used for the window timer. The value of this
attribute is derived from the template used when the port was
initialized. This attribute is valid for protocol class 4 only.
LOCAL NSAP
Local NSAP address being used for the transport connection.
LOCAL REFERENCE
Unique reference number assigned to the transport connection by the
local transport service provider. This attribute applies to COTS only.
LOCAL TRANSPORT SELECTOR
Local transport selector for this port.
MAXIMUM NSDU SIZE
When operating over the CONS, the maximum NSDU size for transmitting
and receiving buffers. Expressed as a number of octets. This attribute
is valid for CONS only.
NEGOTIATED TPDU SIZE
The TPDU size which was negotiated for this transport connection. This
attribute applies to COTS only.
NETWORK PORT
Name of the network service port being used.
NETWORK SERVICE
Type of network service over which the transport connection is
operating. Attribute value derived from the template used when the
port was initialized.
PROTOCOL CLASS
Protocol class operating on the transport connection. This attribute
is not valid for CLTS.
REMOTE IDENTIFIER
Implementation identity and version of the remote NSAP. When present,
this value is received in the identification of implementation
parameter of the CR or CC TPDU. This attribute applies to COTS only.
REMOTE NSAP
Remote NSAP address being used for the transport connection. This
attribute applies to COTS only.
REMOTE REFERENCE
Reference number assigned to the transport connection by the remote
transport service provider. The value will be 0 if the transport
connection is operating the class 0 protocol. This attribute applies
to COTS only.
REMOTE TRANSPORT SELECTOR
Remote transport selector that identifies the remote transport service
user. This attribute applies to COTS only.
REQUEST ACKNOWLEDGMENT
Indicates whether request acknowledgment was negotiated for this
transport connection. This attribute is valid for class 4 protocol only.
RETRANSMIT THRESHOLD
Number of times a TPDU requiring acknowledgment is to be retransmitted
without acknowledgment before the transmission completes with an
error. This attribute is valid for class 4 protocol only.
ROUND-TRIP DELAY ESTIMATE
Current estimate, in milliseconds, of the round-trip delay on the
transport connection. This attribute is valid for protocol class 4
only.
SEND IMPLEMENTATION ID
Indicates whether the implementation id will be sent in the CR. It is
always returned in the CC if it is present in the CR.
SEND PREFERRED MAXIMUM tpdu SIZE
Indicates whether the preferred maximum TPDU size parameter was sent
in the CR or CC TPDU.
SEND REQUEST ACKNOWLEDGMENT
Indicates whether the request acknowledgment parameter was sent in the
CR or CC TPDU.
TYPE
Indicates that the port is being used for the connection-oriented CO
Transport protocol.
CL - Connectionless transport service.
CO - Connection-Oriented transport service.
USE CLNS ERROR REPORTS
When operating over CLNS, indicates whether the network Routing layer's
error reporting facility should be used when performing connection
establishment. This attribute applies to COTS only.