Y.1564 is an Ethernet service activation test methodology. It is the standard for turning up, installing, and troubleshooting
Ethernet and IP-based services. Y.1564 is the only standard test methodology that allows a complete validation of Ethernet
service-level agreements (SLAs) in a single test.
Service performance testing is designed to measure the ability of a Device Under Test (DUT) or a network under test to forward
traffic in different states.
Effective with Cisco IOS XE Everest Release 16.12.1, 10 Gigabit (10G) SAT Internal session is supported. Any SAT session with
a rate-step greater than or equal to 1 Gbps is considered as 10G SAT session.
Cisco implementation
of ITU-T Y.1564 has three key objectives:
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To serve as a network SLA validation tool, ensuring that a service meets its guaranteed performance settings in a controlled
test time.
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To ensure that all services carried by the network, meet their SLA objectives at their maximum committed rate. Thus, proving
that under maximum load, network devices, and paths can support all traffic.
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To perform medium-term and long-term service testing, confirming that network elements can properly carry all services while
under stress during a soaking period.
The following Key Performance Indicators (KPI) metrics indicate the configured SLAs for the service or stream. These following
service acceptance criteria metrics are:
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Information Rate (IR) or throughput—Measures the maximum rate at which none of the offered frames are dropped by the device
under test (DUT). This measurement translates into the available bandwidth of the Ethernet virtual connection (EVC).
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Frame Loss Ratio (FLR)—Measures the number of packets lost from the total number of packets sent. Frame loss can be due to
a number of issues such as network congestion or errors during transmissions.
Table 1. Supported Key Performance Indicators Matrix
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KPI
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FPGA- Based SADT
|
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Internal Direction
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External Direction
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Delay
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Y
|
Y
|
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Jitter
|
Y
|
Y
|
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Loss
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Y
|
Y
|
|
Throughput
|
Y
|
Y
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Note
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SADT Internal sessions do not support ASIC-based SAT.
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Because they interconnect segments, forwarding devices (switches and routers) and network interface units are the basis of
any network. Incorrect configuration of a service on any of these devices within the end-to-end path, can affect the network
performance. This could also lead to potential service outages and network-wide issues such as congestion and link failures.
Service performance testing is designed to measure the ability of DUT or network under test, to forward traffic in different
states. The Cisco implementation of ITU-T Y.1564 includes the following service performance tests:
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Minimum data rate to CIR—Generates bandwidth from the minimum data rate to the committed information rate (CIR) for the test
stream. Measures KPI for Y.1564 to meet configured service acceptance criteria (SAC).
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CIR to EIR—Ramps up bandwidth from the CIR to the excess information rate (EIR) for the test stream. Measures the transfer
rate to ensure that CIR meets the minimum bandwidth of the maximum EIR. Other KPI is not measured.
Note
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In SADT configuration, if the rate of EIR is greater than CIR + EIR, then above EIR is not measured. The stats for Above EIR remains 0 in following command: show ip sla statistics
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Service performance supports four operational modes:
Statistics are calculated, collected, and reported to the IP SLAs module. The statistics database stores historical statistics
pertaining to the operations that are executed.
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One-way statistics collection—Both the passive measurement mode and the traffic generator mode are used along with each other.
One device sends traffic as the generator and another device receives traffic in the passive mode and records the statistics.
The passive mode is distinct from the two-way mode, where the remote device records the statistics instead of looping back
the traffic. The sending device records only the transmit statistics.
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Two-way statistics collection—The sender collects all the measurements. The remote target must be in the loopback mode for
the two-way statistics to work. Loopback mode enables the traffic from the sender to reach the target and sent back to the
sender.
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Passive measurement mode—This mode is enabled by excluding a configured traffic profile. A passive measurement operation does
not generate live traffic. The operation collects only statistics for the target configured for the operation.
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Traffic generator mode—This mode records statistics for the number of packets and bytes transmitted.
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