OSI/TS Configuration and Management Manual

Managing a Transport Connection
OSI/TS Configuration and Management Manual—424831-001
6-9
Application Retry
3. OSI/TS completes the CONTROL 11 call. This completion signals the application
that a connection is established. Nevertheless, it does not correspond to the
exchange of a transport service primitive.
CC-TPDU Parameters
The following paragraphs describe how OSI/TS sets CC-TPDU parameters as a
connection responder. (See Figure 6-1 and the explanation that follows it.)
Since the application issued a CONTROL 11 call, the CC-TPDU cannot contain user
data.
If a CR-TPDU is received and the application has not enabled the connection-
establishment phase for the subdevice, OSI/TS responds with a DR-TPDU. If a
CR-TPDU is received with one or more unrecognizable or invalid parameters, OSI/TS
returns an ER-TPDU.
The CONTROL 11 call remains pending until a valid CR-TPDU is received or until the
call is canceled. An invalid received CR-TPDU does not affect the status of the
CONTROL 11 call.
Application Retry
This subsection describes the error-recovery mechanism provided by the OSI/TS
subsystem during the connection-establishment phase. The steps your application
should take after a connection-establishment failure depend on whether the OSI/TS
subsystem is the connection-establishment initiator or the connection-establishment
responder.
Initial credit OSI/TS returns the lesser of the received value and the
configured value. You can set this parameter using SCF.
DST-REF OSI/TS takes the value in the SRC-REF field of the incoming
CR-TPDU and assigns it to this parameter. OSI/TS includes this
value in all outgoing TPDUs.
SRC-REF OSI/TS assigns a value to this parameter. It uses this value as a
unique internal reference for the transport connection. The
remote peer includes this reference in all TPDUs. OSI/TS uses
the reference to deliver incoming TPDUs to the subdevice
endpoints.
Protocol class OSI/TS returns a value in the CC-TPDU based on the class
proposed by the remote peer entity in the CR-TPDU.
Expedited data If the subdevice is configured for expedited data, OSI/TS returns
the value received in the CR-TPDU.
TPDU size OSI/TS returns the lesser of the configured value and the TPDU
size sent by the remote peer in the CR-TPDU. You can change
the configured value using SCF.