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.