1. ISO 11783/SAE J1939 Network Layer Lecture 6 Network Layer ISO 11783 Part 4, J1939-31 BAE 5030 - 353 Spring 2009 Instructor: Marvin Stone Biosystems and Agricultural Engineering Oklahoma State University Feb 16, 20091BAE 5030-353

2. Purpose of Network Layer Defines functionality of network interconnection units –Segment to segment communication –Network Interconnection Unit tasks Transfer of messages between segments –Forwarding –Filtering –Address translation –Re-packaging –Performance statistics Feb 9, 20092BAE 5030-353

3. Network Interconnection Unit types –Repeater Bit level repeating from one segment to another (physical layer) Adds to effective bus length (propagation delay) –Bridge Receives, stores and forwards messages from one segment to another (data link layer) May filter messages Maximum recommended transit delay is 50 ms –Router May re-map addresses of messages from one segment to another (network layer) Does not allow address claims to pass across –Gateway Interconnects ISO 11783 protocol to different protocols (eg. Ethernet) Feb 9, 2009BAE 5030-3533

4. ISO 11783 System Feb 9, 2009BAE 5030-3534

5. Network Port Identification Port Numbering –Each port on a network interconnection device is numbered for reference. These are standardized in Parts 1 and/or in 4 and 9

6. Network Layer Message –Purpose Acquiring NIU performance statistics Setup and management of filter databases –Control Byte Functions Filter Database Management ( 7 functions) –Setup filtering between port-pairs Access and Reset General and Parametrics ( 3 Functions) –Access or reset general NIU performance data Access and Reset Port-Pair Parametrics ( 3 Functions) –Access or reset port-pair specific NIU performance data Topology query (2 functions) –Access Network Topology Feb 9, 2009BAE 5030-3536

7. Filter Database Management Feb 9, 2009BAE 5030-3537 CommandPGNCommand Byte Data N.MFDB_Request606720Port_Pair N.MFDB_Response606721Port_Pair, Filter Mode, [PGN List] N.MFDB_Add606722Port_Pair, [PGN List] N.MFDB_Delete606723Port_Pair, [PGN List] N.MFDB_Clear606724Port_Pair N.MFDB_Set_Mode606725Port_Pair, Filter Mode N.MFDB_Create_Entry606726Port_Pair, Filter Mode, [PGN List] Port Number Definitions NumberDefinition 0 Local 1-14 Assignable 15 Global (All ports) Filter Mode Definitions ModeDefintion 0 Block specified PGNs (Default = pass all) 1 Pass specified PGNs (Default = block all) 2-250 reserved 251-255 Defined by ISO 11783 Part 7 or J1939-71 Message sent by transport protocol if needed

8. Access and Reset Parameterics FunctionPGN Control ByteOther Data field N.GP_Request60672 128 (80h) Parameter Numbers N.GP_Response60672 129 (81h) Parameter Values N.GP_Reset_Statistics60672 130 (82h) Feb 9, 2009BAE 5030-3538 FunctionPGN Control ByteOther Data field N.SP_Request60672 131 (83h)Port-Pair, Parameter Numbers N.SP_Response60672 132 (84h) Port-Pair, Parameter Values N.SP_Reset_Statistics60672 133 (85h)Port-Pair General Port Specific

9. Access and Reset Parametrics: Parameters Resetable Parameter Number Number of BytesParameter values 0naUsed to request all parameters in numerical order 12 Buffer Size (bytes) 22 Max. Filter Database Size (bytes) 32 Number of Filter Database Entries 42 Max. Messages Received per second 52 Max. Messages Forwarded per second 62 Max. Messages Filtered per second 72 Max. Transit Delay Time (milliseconds) *82 Average Transit Delay Time (milliseconds) *92 # Messages lost due to Buffer Overflow *102 # Messages with Excess Transit Delay Time *112 Average Messages Received per second *122 Average Messages Forwarded per second *132 Average Messages Filtered per second 144 Uptime since last power on reset (seconds) 151 Number of Ports 16 – 253 na Reserved for future assignment by SAE 254 – 255 na See J1939-71 for definitions Feb 9, 2009BAE 5030-3539 Parameters:

10. Topology Query FunctionPGN Control ByteOther Data Field N.NT_Request60672 64 (40h) Port_Pair N.NT_Response60672 65 (41h) Port_Pair, SA List Provision to allow network topology to be determined