2.16.2.9. Yardstick Test Case Description TC011

Packet delay variation between VMs

test case id

OPNFV_YARDSTICK_TC011_PACKET DELAY VARIATION BETWEEN VMs

metric

jitter: packet delay variation (ms)

test purpose

The purpose of TC011 is to evaluate the IaaS network performance with regards to network jitter (packet delay variation). It measures the packet delay variation sending the packets from one VM to the other.

The purpose is also to be able to spot the trends. Test results, graphs and similar shall be stored for comparison reasons and product evolution understanding between different OPNFV versions and/or configurations.

test tool

iperf3

iPerf3 is a tool for active measurements of the maximum achievable bandwidth on IP networks. It supports tuning of various parameters related to timing, buffers and protocols. The UDP protocols can be used to measure jitter delay.

(iperf3 is not always part of a Linux distribution, hence it needs to be installed. It is part of the Yardstick Docker image. As an example see the /yardstick/tools/ directory for how to generate a Linux image with pktgen included.)

test description

iperf3 test is invoked between a host VM and a target VM.

Jitter calculations are continuously computed by the server, as specified by RTP in RFC 1889. The client records a 64 bit second/microsecond timestamp in the packet. The server computes the relative transit time as (server’s receive time - client’s send time). The client’s and server’s clocks do not need to be synchronized; any difference is subtracted outin the jitter calculation. Jitter is the smoothed mean of differences between consecutive transit times.

configuration

File: opnfv_yardstick_tc011.yaml

  • options: protocol: udp # The protocol used by iperf3 tools # Send the given number of packets without pausing: bandwidth: 20m

  • runner: duration: 30 # Total test duration 30 seconds.

  • SLA (optional): jitter: 10 (ms) # The maximum amount of jitter that is accepted.

applicability

Test can be configured with different:

  • bandwidth: Test case can be configured with different

    bandwidth.

  • duration: The test duration can be configured.

  • jitter: SLA is optional. The SLA in this test case

    serves as an example.

usability

This test case is one of Yardstick’s generic test. Thus it is runnable on most of the scenarios.

references

iperf3

ETSI-NFV-TST001

pre-test conditions

The test case image needs to be installed into Glance with iperf3 included in the image.

No POD specific requirements have been identified.

test sequence

description and expected result

step 1

Two host VMs with iperf3 installed are booted, as server and client.

step 2

Yardstick is connected with the host VM by using ssh. A iperf3 server is started on the server VM via the ssh tunnel.

step 3

iperf3 benchmark is invoked. Jitter is calculated and check against the SLA. Logs are produced and stored.

Result: Logs are stored.

step 4

The host VMs are deleted.

test verdict

Test should not PASS if any jitter is above the optional SLA value, or if there is a test case execution problem.