Port loopback with mac-swap and Y.1564 testhead is supported only for Epipe and VPLS services.
ITU-T Y.1564 defines the out-of-service test methodology to be used and parameters to be measured to test service SLA conformance during service turn up. It primarily defines 2 test phases. The first test phase defines service configuration test, which consists of validating whether the service is configured correctly. As part of this test the throughput, Frame Delay, Frame Delay Variation (FDV), and Frame Loss Ratio (FLR) is measured for each service. This test is typically run for a short duration. The second test phase consists of validating the quality of services delivered to the end customer and is referred to as the service performance test. These tests are typically run for a longer duration and all traffic is generated up to the configured CIR for all the services simultaneously and the service performance parameters are measured for each the service.
The 7210 SAS supports service configuration test for user configured rate and measurement of delay, delay variation and frame loss ratio with the testhead OAM tool. The 7210 SAS testhead OAM tool supports bidirectional measurement and it can generate test traffic for only one service at a specific time. It can validate if the user specified rate is available and compute the delay, delay variation and frame loss ratio for the service under test at the specified rate. It is capable of generating traffic up to 1G rate. On some 7210 SAS devices, the user needs to configure the resources of the front-panel port for use with this feature and some other 7210 SAS platforms resources needed for this feature is automatically allocated by software from the internal ports. For more information, see the following Configuration guidelines, to which 7210 SAS platforms need user configuration and on which 7210 SAS platforms software allocates it automatically.
The following figure shows the remote loopback required and the flow of the frame through the network generated by the testhead tool.
The tool allows the user to specify the frame payload header parameters independent of the test SAP configuration parameters to allow the user flexibility to test for different possible frame header encapsulations. This allows user to specify the appropriate VLAN tags, Ethertype, and Dot1p values, independent of the SAP configuration like with actual service testing. That is, the software does not use the parameters (For example: SAP ID, Source MAC, and Destination MAC) during the invocation of the testhead tool to build the test frames. Instead it uses the parameters specified using the frame-payload CLI command tree. The software does not verify that the parameters specified match the service configuration used for testing, for example, software does not match if the VLAN tags specified matches the SAP tags, the Ethertype specified matches the user configured port Ethertype, and so on. It is expected that the user configures the frame-payload appropriately so that the traffic matches the SAP configuration.
The 7210 SAS supports Y.1564 testhead for performing CIR or PIR tests in color-aware mode. With this functionality, users can perform service turn-up tests to validate the performance characteristics (delay, jitter, and loss) for committed rate (CIR) and excess rate above CIR (that is, PIR rate). The testhead OAM tool uses the in-profile packet marking value and out-of-profile packet marking value, to differentiate between committed traffic and PIR traffic in excess of CIR traffic. Traffic within CIR (that is, committed traffic) is expected to be treated as in-profile traffic in the network and traffic in excess of CIR (that is, PIR traffic) is expected to be treated as out-of-profile traffic in the network, allowing the network to prioritize committed traffic over PIR traffic. The testhead OAM tool allows the user to configure individual thresholds for green or in-profile packets and out-of-profile or yellow packets. It is used by the testhead OAM tool to compare the measured value for green or in-profile packets and out-of-profile or yellow packets against the configured thresholds and report success or failure.
The functionality listed as follows is supported by the testhead OAM tool:
Supports configuration of only access SAPs as the test measurement point.
Supports all port encapsulation supported on all service SAP types, with some exceptions as noted in the following Configuration guidelines.
Supported for only VPLS and Epipe service.
Supports two-way measurement of service performance metrics. The tests measure throughput, frame delay, frame delay variation, and frame loss ratio.
For two-way measurement of the service performance metrics, such as frame delay and frame delay variation, test frames (also called as marker packets) are injected at a low rate at periodic intervals. Frame delay and Frame delay variation is computed for these frames. Hardware-based timestamps are used for delay computation.
The 7210 SAS supports configuration of a rate value and provides an option to measure the performance metrics. The testhead OAM tool generates traffic up to the specified rate and measures service performance metrics such as delay, jitter, and loss for in-profile and out-of-profile traffic.
Testhead tool can generate traffic up to about 1G rate. CIR and PIR rate can be specified by the user and is rounded off the nearest rate the hardware supports by using the adaptation rule configured by the user.
Allows the user to specify the different frame-sizes from 64 bytes - 9212 bytes.
User can configure the following frame payload types: L2 payload, IP payload, and IP/TCP/UDP payload. Testhead tool will use the configured values for the IP header fields and TCP header fields based on the payload type configured. User is provided with an option to specify the data pattern to used in the payload field of the frame/packet.
Allows the user to configure the duration of the test up to a maximum of 24 hours, 60 minutes, and 60 seconds. The test performance measurements by are done after the specified rate is achieved. At any time user can probe the system to know the current status and progress of the test.
Supports configuration of the Forwarding Class (FC). It is expected that user will define consistent QoS classification policies to map the packet header fields to the FC specified on the test SAP ingress on the local node, in the network on the nodes through which the service transits, and on the SAP ingress in the remote node.
Allows the user to configure a test-profile, also known as, a policy template that defines the test configuration parameters. User can start a test using a preconfigured test policy for a specific SAP and service. The test profile allows the user to configure the acceptance criteria. The acceptance criteria allows user to configure the thresholds that indicates the acceptable range for the service performance metrics. An event is generated if the test results exceed the configured thresholds. For more information, see the following CLI section.
At the end of the test, the measured values for FD, FDV, and FLR are compared against the configured thresholds to determine the PASS or FAIL criteria and to generate a trap to the management station. If the acceptance criteria is not configured, the test result is declared to be PASS, if the throughput is achieved and frame-loss is 0 (zero).
ITU-T Y.1564 specifies different test procedures as follows. CIR and PIR configuration tests are supported by the testhead tool, as follows:
CIR and PIR configuration test (color-aware and non-color aware).
Traffic policing test (color-aware and non-color aware) is supported. Traffic policing tests can be executed by the user by specifying a PIR to be 125% of the desired PIR. Traffic policing test can be executed in either color-aware mode or color-blind (non-color-aware) mode.
ITU-T Y.1564 specifies separate test methodology for color-aware and non-color-aware tests. The standard requires a single test to provide the capability to generate both green-color/in-profile traffic for rates within CIR and yellow-color or out-of-profile traffic for rates above CIR and within EIR. The 7210 SAS testhead marks test packets appropriately when generating the traffic, as SAP ingress does not support color-aware metering, it is not possible to support EIR color-aware, and traffic policing color-aware tests end-to-end in a network (that is, from test SAP to test SAP). Instead, It is possible to use the tests to measure the performance parameters from the other endpoint (example Access-uplink SAP) in the service, through the network, to the remote test SAP, and back again to the local test SAP.
The 7210 SAS Y.1564 testhead is applicable only for VPLS and Epipe services.