This blog introduces test specifications by OPEN(One Pair EtherNet) Alliance for OSI layer and switch. These tests must be referred to by car manufacturers within their quality control process. The OPEN Alliance (One-Pair Ether-Net) Special Interest Group (SIG) is a non-profit, open industry alliance of mainly automotive industry and technology providers collaborating to encourage wide-scale adoption of Ethernet-based networks as the standard in automotive networking applications.

OPEN alliance comprises different Technical Committees(TC). Following are the technical committees of OPEN alliance,

1. 100BASE-T1 Ethernet Channel & Components
2. 1000BASE-T1 CMC Requirements
3. Automotive Ethernet Tooling 
4. Gap Identification
5. Common xMII Interface Definition
6. 1000BASE-RH Gigabit Ethernet over Plastic-Optical-Fiber (GEPOF)
7. Automotive Ethernet ECU Test Specification
8. Automotive Ethernet Channel & Components
9. Automotive Ethernet Sleep/Wake-Up
10. Ethernet switch requirements and qualification
11. Test specifications for the compliance testing of IEEE 1000BASE-T1 (IEEE802.3bp, Cause 97) Physical Interface (PHY) devices
12. TC13 – New Test House Qualification Requirements
13. TC14 – Interoperability & Compliance Tests for 10BASE-T1S PHYs

In this blog, we will look into TC8(Automotive Ethernet Channel & Components) and TC11(Test specifications for the compliance testing of IEEE 1000BASE-T1) specifications.

TC8:

TC8 is ECU and Network Test Specification designed to determine if a product conforms to specifications defined in OPEN Specifications or related requirements. This specification is a collection of all test cases which are recommended to be considered for automotive use and should be referred by car manufacturers within their quality control processes. Successful execution and passing all relevant tests gives a Device Under Test (DUT) a minimum approval that the device’s basic implementations are done correctly.

This Test specification document is grouped in several chapters oriented on the scopes: “Automotive Ethernet”, “TCP/IP Protocol Family” and “Automotive Protocols”. Tests are organized and identified with distinct IDs that relate to their scopes, and a unique enumeration. Figure 1 depicts protocol specifications for different TCP IP layers.

Number of tests in each category of specification is shown in Figure 2(Reference [3]).

Test setup for “TCP/IP Protocol Family” and “Automotive Protocols” is simple as depicted in Figure 3. The setup in Figure 3 depicts that the tests can be performed using a single interface on the test bench and DUTS side, referred to as TIface-0 and DIface-0 respectively. But Layer 1 testing of “Automotive Ethernet” protocol testing needs specialized equipment as shown in Figure 4 for OABR_LINKUP_01, “Shall ensure that the link is established within a given time without a high time variation”. The layer 1 test setup in Figure 4 shows the need for a “Golden device” for measuring link setup time of DUT’s phy. In Figure 4, CON represents an RJ45 connector interface. “Automotive Ethernet”  protocol for Layer 2 mainly tests the switch functionality. The test setup for the Layer2 testing is shown in Figure 5.

In order to execute “TCP/IP Protocol Family” and “Automotive Protocols”, one must have a test system with at least two Ethernet ports. One port will be used as back end communication to send commands to DUT the second one will contain traffic as per test specifications.

TC11:

C11, Switch Semiconductor Test Specification is designed to determine if a product conforms to specifications defined in OPEN Specifications or related requirements. This specification is a collection of all test cases which are recommended to be considered for automotive use and should be referred by car manufacturers within their quality control processes. Successful execution and passing all relevant tests gives Switch Semiconductors a minimum approval that the device’s basic implementations are done correctly.

TC11 test specifications can be divided into following categories broadly,

1. Functionality tests
   Port mirroring, packet blocking, packet forwarding, handling of the jumbo frame, support for VLAN tag. There are a total of 110 functional tests.
2. Time Sensitive tests
   These tests need specialized equipment like high bandwidth Oscilloscope that can capture signal rate at 10G to measure timing at the physical layer level. There is a total of 7 such test cases. These tests require capturing the instance of time and check if the measured time is within the allowed range.
   Following tests belongs to time-sensitive tests,
   2.2.1.3 MAC_to_MAC_delay
   2.2.2.1 Boot_time_with_PHYs
   2.2.2.2 Boot_time_without_PHYs
   2.3.5 Address_Learning_ageing
   2.3.6 Address_Learning_ageing_time
   2.4.1.2 Setup/Verification Tests – 2
3. Frame Alteration tests
   These are negative test cases that are used to validate the response of switches to malformed packets. These tests may require programmable hardware to modify Ethernet packet fields. There are 6 such test cases. Following tests belongs to frame alteration tests,
   2.2.1.1 Operate_as_Store_and_Forward_Switch
   2.2.3 IEEE 802.1X Port-Based Security – 2
   2.9.1.5 EtherStats_Octets
   2.2.13 Block untagged frames with invalid length in the length/type field
   2.2.14 Block tagged frames with invalid length in the length/type field

All the test case executions are not mandatory for compliance. There are 119 mandatory test cases that must be executed for compliance and 21 optional test cases. Following chart summarizes the category of test cases.

Following is the typical test setup for execution of TC11 test cases. In the following setup, DUT is the switch which is to be tested.

The test station is programmable hardware like FPGA, which is a traffic generator and configurable hardware to program the ethernet packet fields as per test case  requirement(Negative test cases).

The “Test Station Control” configures “Test Station” for Ethernet header field programming requirements for negative test cases and traffic pattern as per test case requirement.

“DUT configuration” is for configuring the switch parameters like mirroring requirements as per test cases.

“Master Control” is a centralized system for test control and test result capture. Vayavya provides test infrastructure known as Rossum which can be used on “Master Control”, “Test Station Control” and “DUT Configuration” to realize TC11 test execution and result capture.

Test Case Compliance Certification

In order to certify that the DUT complies to TC8/TC11 test specifications, these tests have to be executed by a certified “Test House”.

OPEN Alliance specifies some requirements on “Test House”, the firm that performs the test

• Test House must be ISO 17025 accredited
• Test House must be neutral
• Test House must have relevant technical experience
• Test House Personnel(Regarding experience and competence fo tester)
• Membership and Cooperation(Must be technical member of OPEN Alliance)

There are many vendors in the market who have solutions for TC8, but none of them explicitly are known to be qualified “Test House”. These vendors mainly provide layer 3 to layer 5 test cases and they rely on vendors like Tecktronics for Layer 1 tests.

References:

[1] TC11 specification TC11_TestSpecification_Switch_V1.0_final-2019.pdf

[2] TC8 specification 9_OA_Automotive_Ethernet_ECU_TestSpecification_v1.pdf

[3] TC8 Conformance Testing of Automotive Ethernet Networks from vector