diff --git a/index.rst b/index.rst
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--- a/index.rst
+++ b/index.rst
@@ -45,6 +45,7 @@
    testing/acceptance_specification
    testing/pdp_testing
    testing/fabric_testing
+   testing/sdcore_testing
 
 .. toctree::
    :maxdepth: 1
diff --git a/testing/sdcore_testing.rst b/testing/sdcore_testing.rst
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@@ -0,0 +1,255 @@
+..
+   SPDX-FileCopyrightText: © 2021 Open Networking Foundation <support@opennetworking.org>
+   SPDX-License-Identifier: Apache-2.0
+
+SD-Core Testing
+===============
+
+Test Framework
+--------------
+
+NG40
+~~~~
+
+Overview
+^^^^^^^^
+
+NG40 tool is used as RAN emulator in SD-Core testing. NG40 runs inside a VM
+which is connected to both Aether control plane and data plane. In testing
+scenarios that involve data plane verifications, NG40 also emulates a few
+application servers which serve as the destinations of data packets.
+
+A typical NG40 test case involves UE attaching, data plane verifications and
+UE detaching. During the test NG40 acts as UEs and eNBs and talks to the
+mobile core to complete attach procedures for each UE it emulates. Then NG40
+verifies that data plane works for each attached UE by sending traffic between
+UEs and application servers. Before finishing each test NG40 performs detach
+procedures for each attached UE.
+
+Test cases
+^^^^^^^^^^
+
+Currently the following NG40 test cases are implemented:
+
+1. ``4G_M2AS_PING_FIX`` (attach, dl ping, detach)
+2. ``4G_M2AS_UDP`` (attach, dl+ul udp traffic, detach)
+3. ``4G_M2AS_TCP`` (attach, relaese, service request, dl+ul tcp traffic, detach)
+4. ``4G_AS2M_PAGING`` (attach, release, dl udp traffic, detach)
+5. ``4G_M2AS_SRQ_UDP`` (attach, release, service request, dl+ul udp traffic)
+6. ``4G_M2CN_PS`` (combined IMSI/PTMSI attach, detach)
+7. ``4G_HO`` (attach, relocate and ping, detach)
+8. ``4G_SCALE`` (attach with multiple UEs, ping, detach)
+
+All the test cases are parameterized and can take arguments to specify number
+of UEs, attach/detach rate, traffic type/rate etc. For example, ``4G_SCALE``
+test case can be configured as a mini scalability test which performs only 5
+UE attaches in a patchset pre-merge test, while in the nightly tests it can
+take different arguments to run 10K UE attaches with a high attach rate.
+
+Test suites
+^^^^^^^^^^^
+
+The test cases are atomic testing units and can be combined to build test
+suites. The following test suites have been built so far:
+
+* ``functionality test suite`` verifies basic functionality of the
+  mobile core. It runs test case #1 to #8 including ``4G_SCALE`` which attaches
+  5 UEs with 1/s attach rate
+
+* ``scalability test suite`` tests the system by scale and verifies
+  system stability. It runs ``4G_SCALE`` which attaches a large number of UEs
+  with high attach rate (16k UEs with 100/s rate on dev pod, and 10k UEs with
+  10/s rate on staging pod)
+
+* ``performance test suite`` measures performance of the control and
+  data plane. It runs ``4G_SCALE`` multiple times with different attach rates
+  to understand how the system performs under different loads.
+
+Robot Framework
+~~~~~~~~~~~~~~~
+
+Robot Framework was chosen to build test cases that involve interacting with
+not only NG40 but also other parts of the system. In these scenarios Robot
+Framework acts as a high level orchestrator which drives various components
+of the system using component specific libraries including NG40.
+
+Currently the ``Integration test suite`` is implemented using Robot
+Framework. In the integration tests Robot Framework calls ng40 library to
+perform normal attach/detach procedures. Meanwhile it injects failures into
+the system (container restarts, link down etc.) by calling functions
+implemented in the k8s library.
+
+The following integration tests are implemented at the moment:
+
+* Subscriber Attach with HSS Restart
+* Subscriber Attach with MME Restart
+* Subscriber Attach with SPGWC Restart
+* Subscriber Attach with PFCP Agent Restart
+
+.. Note::
+   More integration tests are being developed as part of Robot Framework
+
+Test Schedules
+--------------
+
+Nightly Tests
+~~~~~~~~~~~~~
+
+Overview
+^^^^^^^^
+
+SD-Core nightly tests are a set of jobs managed by Aether Jenkins.
+All four test suites we mentioned above are scheduled to run nightly.
+
+* ``functionality job (func)`` runs NG40 test cases included in the
+  functionality suite and verifies all tests pass.
+
+* ``scalability job (scale)`` runs the scalability test suite and reports
+  the number of successful/failed attaches, detaches and pings.
+
+* ``performance job (perf)`` runs the performance test suite and reports
+  SCTP heartbeat RTT, GTP ICMP RTT and call setup latency numbers.
+
+And all these jobs can be scheduled on any of the Aether PODs including
+``dev`` pod, ``staging`` pod and ``qa`` pod. By combining the test type and
+test pod the following Jenkins jobs are generated:
+
+* ``dev`` pod: `func_dev`, `scale_dev`, `perf_dev`, `integ_dev`
+* ``staging`` pod: `func_staging`, `scale_staging`, `perf_staging`, `integ_staging`
+* ``qa`` pod: `func_qa`, `scale_qa`, `perf_qa`, `integ_qa`
+
+Job structure
+^^^^^^^^^^^^^
+
+Take `scale_dev` job as an example. It runs the following downstream jobs:
+
+* `omec_deploy_dev`: this job re-deploys the dev pod with latest OMEC images.
+
+.. Note::
+   only the dev pod job triggers a deployment downstream job. No
+   re-deployment is performed on the staging and qa pod before the tests
+
+* `ng40-test_dev`: this job executes the scalability test suite.
+
+* `archive-artifacts_dev`: this job collects and uploads k8s and container logs.
+
+* `post-results_dev`: this job collects the NG40 test logs/pcaps and pushes the
+  test data to database. It also generates plots using Rscript for func and
+  scale tests
+
+The integration tests are written using Robot Framework so have a slightly
+different Jenkins Job structure. Take `integ_dev` as an example. It runs the
+following downstream jobs:
+
+* `omec_deploy_dev`: this job executes the scalability test suite.
+
+* `robotframework-test_dev`: this job is similar to `ng40-test_dev` with the
+  exception that instead of directly executing NG40 commands it calls robot
+  framework to exectue the test cases and publishes the test results using
+  `RobotPublisher` Jenkins plugin. The robot results will also be copied to
+  the upstream job and published there.
+
+* `archive-artifacts_dev`: this job collects and uploads k8s and container logs.
+
+* `post-results_dev`: this job collects the NG40 test logs/pcaps and pushes the
+  test data to database. It also generates plots using Rscript for func and
+  scale tests
+
+Patchset Tests
+~~~~~~~~~~~~~~
+
+Overview
+^^^^^^^^
+
+SD-Core pre-merge verifications cover the following Github repos: ``c3po``,
+``Nucleus``, ``upf-epc`` and ``spgw`` (private). OMEC CI includes the following
+verifications:
+
+* ONF CLA verification
+* License verifications (FOSSA/Reuse)
+* NG40 tests
+
+These verifications are automatically triggered by submitted or updated PR to
+the repos above. They can also be triggered manually by commenting ``retest
+this please`` to the PR. At this moment only CLI and NG40 verifications are
+mandatory.
+
+The NG40 verifications are a set of jobs running on both opencord Jenkins and
+Aether Jenkins (private). The jobs run on opencord Jenkins include
+
+* `omec_c3po_container_remote <https://jenkins.opencord.org/job/omec_c3po_container_remote/>`_ (public)
+
+* `omec_Nucleus_container_remote <https://jenkins.opencord.org/job/omec_Nucleus_container_remote/>`_ (public)
+
+* `omec_upf-epc_container_remote <https://jenkins.opencord.org/job/omec_upf-epc_container_remote/>`_ (public)
+
+* `omec_spgw_container_remote` (private, under member-only folder)
+
+And the jobs run on Aether Jenkins include
+
+* `c3po_premerge_dev`
+
+* `Nucleus_premerge_dev`
+
+* `upf-epc_premerge_dev`
+
+* `spgw_premerge_dev`
+
+Job structure
+^^^^^^^^^^^^^
+
+Take c3po jobs as an example. c3po PR triggers a public job `omec_c3po_container_remote <https://jenkins.opencord.org/job/omec_c3po_container_remote/>`__
+job running on opencord Jenkins through Github webhooks,
+which then triggers a private job `c3po_premerge_dev` running on Aether Jenkins
+using a Jenkins plugin called `Parameterized Remote Trigger Plugin <https://www.jenkins.io/doc/pipeline/steps/Parameterized-Remote-Trigger/>`__.
+
+The private c3po job runs the following downstream jobs sequentially:
+
+* `docker-publish-github_c3po`: this job downloads the c3po PR, runs docker
+  build and publishes the c3po docker images to `Aether registry`.
+
+* `omec_deploy_dev`: this job deploys the images built from previous job onto
+  the omec dev pod.
+
+* `ng40-test_dev`: this job executes the functionality test suite.
+
+* `archive-artifacts_dev`: this job collects and uploads k8s and container logs.
+
+After all the downstream jobs are finished, the upstream job (`c3po_premerge_dev`)
+copies artifacts including k8s/container/NG40 logs and pcap files from
+downstream jobs and saves them as Jenkins job artifacts.
+
+These artifacts are also copied to and published by the public job
+(`omec_c3po_container_remote <https://jenkins.opencord.org/job/omec_c3po_container_remote/>`__)
+on opencord Jenkins so that they can be accessed by the OMEC community.
+
+Pre-merge jobs for other OMEC repos share the same structure.
+
+Post-merge
+^^^^^^^^^^
+
+The following jobs are triggered as post-merge jobs when PRs are merged to
+OMEC repos:
+
+* `docker-publish-github-merge_c3po`
+
+* `docker-publish-github-merge_Nucleus`
+
+* `docker-publish-github-merge_upf-epc`
+
+* `docker-publish-github-merge_spgw`
+
+Again take the c3po job as an example. The post-merge job (`docker-publish-github-merge_c3po`)
+runs the following downstream jobs sequentially:
+
+* `docker-publish-github_c3po`: this is the same job as the one in pre-merge
+  section. It checks out the latest c3po code, runs docker build and
+  publishes the c3po docker images to `docker hub <https://hub.docker.com/u/omecproject>`__.
+
+.. Note::
+   the spgw images are published to Aether registry instead of docker hub
+
+* `c3po_postrelease`: this job submits a patchset to aether-pod-configs repo
+  for updating the CD pipeline with images published in the job above.
+
+Post-merge jobs for other OMEC repos share the same structure.