ISO 8073 / TP
Connection-Oriented Transport Protocol
Move the mouse pointer to any protocol field and press the left mouse button.
TP is a connection-oriented transport protocol as part of the ISO protocol suite.
There are five TP classes:
1. class 0 - simple class
2. class 1 - basic error recovery class
3. class 2 - multiplexing class
4. class 3 - error recovery and multiplexing class
5. class 4 - error detection and recovery class
Each class has its own PDU structure. These are the different TPDUs (=TP-PDUs):
CR TPDU - connection request TPDU
CC TPDU - connection confirm TPDU
DR TPDU - disconnect request TPDU
DC TPDU - disconnect confirm TPDU
DT TPDU - data TPDU
ED TPDU - expedited data TPDU
AK TPDU - data acknowledge TPDU
EA TPDU - expedited acknowledge TPDU
RJ TPDU - reject TPDU
ER TPDU - error TPDU
TPDUs consist of (a) a length indicator (LI), (b) a fixed part preceded by a 'TPDU code', (c) an optional variable part, (d) optional user data.
The fixed parts are different between the various TPDU types but always unchanged within the same TPDU type.
Each TPDU's fixed part has a 'TPDU code'. This code needs only 4 bits; the remaining 4 bits are unused or used for CDT (credit) indication.
The variable parts may have one ore more of these parameters:
1000 0101 Acknowledge Time
1000 0110 Residual Error Rate
1000 0111 Priority
1000 1000 Transit Delay
1000 1001 Throughput
1000 1010 Subsequence Number
1000 1011 Reassignment Time
1000 1100 Flow Control Confirmation
1100 0000 TPDU Size
1100 0001 Invalid TPDU
1100 0001 TSAP-ID / calling TSAP
1100 0010 TSAP-ID / called TSAP
1100 0011 Checksum
1100 0100 Version Number
1100 0101 Protection Parameters (user defined)
1100 0110 Additional Option Selection
1100 0111 Alternative Protocol Classes
See:
Variable Part (n bytes)
CR TPDU Header
CC TPDU Header
DR TPDU Header
DC TPDU Header
DT TPDU Header
ED TPDU Header
AK TPDU Header
EA TPDU Header
RJ TPDU Header
ER TPDU Header