diff --git a/docs/sections/installation_oom.rst b/docs/sections/installation_oom.rst
index cc5538a..789e018 100644
--- a/docs/sections/installation_oom.rst
+++ b/docs/sections/installation_oom.rst
@@ -340,4 +340,4 @@
 
 To undeploy the DCAE services deployed via Helm (the hv-ves-collector, ves-collector, tcagen2,
 and prh), use the ``helm undeploy`` command against the `top_level_release_name`-``dcaegen2-services``
-Helm sub-release.
\ No newline at end of file
+Helm sub-release.
diff --git a/docs/sections/release-notes.rst b/docs/sections/release-notes.rst
index 116e996..d74f0da 100644
--- a/docs/sections/release-notes.rst
+++ b/docs/sections/release-notes.rst
@@ -15,6 +15,257 @@
 ..
 
 
+..      ==========================
+..      * * *    ISTANBUL    * * *
+..      ==========================
+
+
+Version: 9.0.0
+==============
+
+
+Abstract
+--------
+
+This document provides the release notes for Istanbul release.
+
+Summary
+-------
+
+Following DCAE components are available with default ONAP/DCAE installation.
+
+    - Platform components
+
+        - Cloudify Manager (helm chart)*
+        - Bootstrap container (helm chart)*
+        - Configuration Binding Service (helm chart)
+        - Deployment Handler (helm chart)*
+        - Policy Handler (helm chart*
+        - Service Change Handler (helm chart)*
+        - Inventory API (helm chart)*
+        - Dashboard (helm chart)*
+        - VES OpenAPI Manager (helm chart)
+
+    - Service components
+
+        - VES Collector (helm chart  & cloudify blueprint)
+        - HV-VES Collector (helm chart  & cloudify blueprint)
+        - PNF-Registration Handler  (helm chart  & cloudify blueprint)
+        - Docker based Threshold Crossing Analytics (TCA-Gen2) (helm chart  & cloudify blueprint)
+
+    - Additional resources that DCAE utilizes deployed using ONAP common charts:
+
+        - Postgres Database
+        - Mongo Database
+        - Consul Cluster
+
+    \*  These components will be retired next ONAP release as cloudify deployments will be diabled after Istanbul.
+ 
+
+Below service components (mS) are available to be deployed on-demand (helm chart & Cloudify Blueprint)
+
+ 	- SNMPTrap Collector
+ 	- RESTConf Collector
+ 	- DataFile Collector
+ 	- PM-Mapper
+ 	- BBS-EventProcessor
+ 	- VES Mapper
+ 	- Heartbeat mS
+ 	- SON-Handler
+ 	- PM-Subscription Handler
+ 	- DataLake Handler (Admin and Feeder)
+ 	- Slice Analysis mS
+ 	- DataLake Extraction Service
+ 	- KPI-Ms
+
+
+Under OOM all DCAE component containers are deployed as Kubernetes Pods/Deployments/Services into Kubernetes cluster.
+With DCAE tranformation to Helm in Istanbul release - all DCAE components are available to be deployed under Helm; Cloudify blueprint deployment is provided for backward compatibility support in this release.
+
+For Helm managed microservices, the dependencies/pre-requisite are identified on each charts individually. In general, most DCAE microservice rely on Consul/Configbindingservice for sourcing configuration updates (this dependency will be removed in next release). Each microservice can be deployed independently and based on dcaegen2-services-common template, features can be enabled or disabled via configuration override during deployment. For list of supported features in helm refer - :doc:`Using Helm to deploy DCAE Microservices <./dcaeservice_helm_template>`.
+
+DCAE continues to provides Cloudify deployment through plugins (cloudify) that is capable of expanding a Cloudify blueprint node specification for a service component to a full Kubernetes specification, with additional enhancements such as replica scaling, sidecar for logging to ONAP ELK stack.
+
+
+Release Data
+------------
+
++--------------------------------------+--------------------------------------------------------+
+| **DCAE Project**                     |                                                        |
+|                                      |                                                        |
++--------------------------------------+--------------------------------------------------------+
+| **Docker images**                    | Refer :any:`Deliverable <istanbul_deliverable>`        |
+|                                      |                                                        |
++--------------------------------------+--------------------------------------------------------+
+| **Release designation**              | 9.0.0 Istanbul                                         |
+|                                      |                                                        |
++--------------------------------------+--------------------------------------------------------+
+| **Release date**                     | 2021-10-28                                             |
+|                                      |                                                        |
++--------------------------------------+--------------------------------------------------------+
+
+
+New features
+------------
+
+
+
+*DCAE Enhancements Features*
+
+
+DCAEGEN2-2771 DCAE Impacts for E2E Network Slicing in Istanbul release
+    - Enhance SliceAnalysis and KPI-Computation MS to interface with CPS; integration with new CBS client SDK and support policy sidecar
+
+DCAEGEN2-2703 Add stndDefined domain to HV-VES
+	- Adapt HV_VES to support stdDefined domain instroduced under VES7.2.1 spec 
+
+DCAEGEN2-2630 DCAE Helm Transformation (Phase 2)
+	- Since Honolulu, 13 additional MS has been delivered for Helm deployment
+	- DCAE Service helm deployment is supported through implementing common functions as named template/functions defined in dcaegen2-services-common charts. Several new common features has been added in generic fashion and components/mS can enable required features via configuration override
+			- K8S Secret/Environment mapping
+			- CMPv2 Certificate support
+			- Policy Sidecar
+			- Mount data from configmap through PV/PVC
+			- Topic/feed provisioning support
+	- SDK Libraries (java and python) has been enhanced to support configuration retrieval from files
+	- Helm-generator tool available for generating DCAE component helm-chart given component spec
+
+DCAEGEN2-2541 Bulk PM (PMSH) - Additional use cases, deployment and documentation enhancements
+	- Enhanced PMSH Microservice to support subscription property updates, config updates to support 'n' subscriptions, support resource name in filter
+
+DCAEGEN2-2522 Enhancements for OOF SON use case
+	- Implemented CPS client and switched to new CBS client SDK for removing consul dependency and enabling policy configuration through sidecar.
+
+Non-Functional
+
+   - Removed GPLv3 license from software by switching to onap/integration base images (DCAEGEN2-2455)
+   - CII Badging improvements (DCAEGEN2-2622)
+   - Healthcheck container Py3 upgrade  (DCAEGEN2-2737)
+   - Vulnerability updates for several DCAE MS (TCA-gen2, DataFileCollector,RESTConf, VES,Mapper, PM-Mapper, PRH, SON-handler, KPI-MS, Slice-Analysis MS) (DCAEGEN2-2768)
+
+
+Bug Fixes
+
+   - BPGenerator yaml Fixes are different for yaml file and string (DCAEGEN2-2489)
+   - Slice Analysis - Avoid removal of data when insufficient samples are present (DCAEGEN2-2509)
+
+
+
+.. _istanbul_deliverable:
+
+Deliverables
+------------
+
+Software Deliverables
+
+.. csv-table::
+   :header: "Repository", "SubModules", "Version & Docker Image (if applicable)"
+   :widths: auto
+
+   "dcaegen2/analytics/tca-gen2", "", "onap/org.onap.dcaegen2.analytics.tca-gen2.dcae-analytics-tca-web:1.3.1"
+   "dcaegen2/collectors/datafile", "", "onap/org.onap.dcaegen2.collectors.datafile.datafile-app-server:1.6.1"
+   "dcaegen2/collectors/hv-ves", "", "onap/org.onap.dcaegen2.collectors.hv-ves.hv-collector-main:1.9.1"
+   "dcaegen2/collectors/restconf", "", "onap/org.onap.dcaegen2.collectors.restconfcollector:1.2.5"
+   "dcaegen2/collectors/snmptrap", "", "onap/org.onap.dcaegen2.collectors.snmptrap:2.0.5"
+   "dcaegen2/collectors/ves", "", "onap/org.onap.dcaegen2.collectors.ves.vescollector:1.10.1"
+   "dcaegen2/deployments", "cm-container", "onap/org.onap.dcaegen2.deployments.cm-container:4.6.1"
+   "dcaegen2/deployments", "consul-loader-container", "onap/org.onap.dcaegen2.deployments.consul-loader-container:1.1.1"
+   "dcaegen2/deployments", "dcae-k8s-cleanup-container", "onap/org.onap.dcaegen2.deployments.dcae-k8s-cleanup-container:1.0.0"
+   "dcaegen2/deployments", "healthcheck-container", "onap/org.onap.dcaegen2.deployments.healthcheck-container:2.2.0"
+   "dcaegen2/deployments", "tls-init-container", "onap/org.onap.dcaegen2.deployments.tls-init-container:2.1.0"
+   "dcaegen2/deployments", "dcae-services-policy-sync", "onap/org.onap.dcaegen2.deployments.dcae-services-policy-sync:1.0.1"
+   "dcaegen2/platform", "mod/onboardingapi", "onap/org.onap.dcaegen2.platform.mod.onboardingapi:2.12.5"
+   "dcaegen2/platform", "mod/distributorapi", "onap/org.onap.dcaegen2.platform.mod.distributorapi:1.1.0"
+   "dcaegen2/platform", "mod/designtool", "onap/org.onap.dcaegen2.platform.mod.designtool-web:1.0.2"
+   "dcaegen2/platform", "mod/genprocessor", "onap/org.onap.dcaegen2.platform.mod.genprocessor-http:1.0.2"
+   "dcaegen2/platform", "mod/genprocessor", "onap/org.onap.dcaegen2.platform.mod.genprocessor-job:1.0.2"
+   "dcaegen2/platform", "mod/designtool/mod-registry", "onap/org.onap.dcaegen2.platform.mod.mod-registry:1.0.0"
+   "dcaegen2/platform", "mod/runtimeapi", "onap/org.onap.dcaegen2.platform.mod.runtime-web:1.2.3"
+   "dcaegen2/platform", "adapter/acumos", "onap/org.onap.dcaegen2.platform.adapter.acumos:1.0.6"
+   "dcaegen2/platform/blueprints", "", "onap/org.onap.dcaegen2.deployments.k8s-bootstrap-container:3.3.5"
+   "dcaegen2/platform/configbinding", "", "onap/org.onap.dcaegen2.platform.configbinding:2.5.4"
+   "dcaegen2/platform/deployment-handler", "", "onap/org.onap.dcaegen2.platform.deployment-handler:4.4.1"
+   "dcaegen2/platform/inventory-api", "", "onap/org.onap.dcaegen2.platform.inventory-api:3.5.2"  
+   "dcaegen2/platform/policy-handler", "", "onap/org.onap.dcaegen2.platform.policy-handler:5.1.3"
+   "dcaegen2/platform/servicechange-handler", "", "onap/org.onap.dcaegen2.platform.servicechange-handler:1.4.0"
+   "dcaegen2/platform/ves-openapi-manager", "", "onap/org.onap.dcaegen2.platform.ves-openapi-manager:1.0.1"
+   "dcaegen2/services", "components/datalake-handler", "onap/org.onap.dcaegen2.services.datalakefeeder:1.1.1"
+   "dcaegen2/services", "components/datalake-handler", "onap/org.onap.dcaegen2.services.datalakeadminui:1.1.1"
+   "dcaegen2/services", "components/datalake-handler", "onap/org.onap.dcaegen2.services.datalake.exposure.service:1.1.1"
+   "dcaegen2/services", "components/pm-subscription-handler", "onap/org.onap.dcaegen2.services.pmsh:1.3.2"
+   "dcaegen2/services", "components/slice-analysis-ms", "onap/org.onap.dcaegen2.services.components.slice-analysis-ms:1.0.6"
+   "dcaegen2/services", "components/bbs-event-processor", "onap/org.onap.dcaegen2.services.components.bbs-event-processor:2.1.1"
+   "dcaegen2/services", "components/kpi-ms", "onap/org.onap.dcaegen2.services.components.kpi-ms:1.0.1"
+   "dcaegen2/services/heartbeat", "", "onap/org.onap.dcaegen2.services.heartbeat:2.3.1"
+   "dcaegen2/services/mapper", "", "onap/org.onap.dcaegen2.services.mapper.vesadapter.universalvesadaptor:1.3.0"
+   "dcaegen2/services/pm-mapper", "", "onap/org.onap.dcaegen2.services.pm-mapper:1.7.2"
+   "dcaegen2/services/prh", "", "onap/org.onap.dcaegen2.services.prh.prh-app-server:1.7.1"
+   "dcaegen2/services/son-handler", "", "onap/org.onap.dcaegen2.services.son-handler:2.1.4"
+   "dcaegen2/platform", "mod/bpgenerator", "Blueprint Generator 1.8.0 (jar)"
+   "dcaegen2/services/sdk", "", "DCAE SDK 1.8.7 (jar)"
+   "ccsdk/dashboard", "", "onap/org.onap.ccsdk.dashboard.ccsdk-app-os:1.4.4"
+
+
+Known Limitations, Issues and Workarounds
+-----------------------------------------
+
+DCAEGEN2-2861 - Topic/feed provisioned through Helm require manual cleanup once the helm deployed service are uninstalled.
+Refer following document  :doc:`Using Helm to deploy DCAE Microservices <./dcaeservice_helm_template>` for steps to remove topic/feed provisioned in DMAAP.
+
+
+*Known Vulnerabilities*
+
+None
+
+*Workarounds*
+
+Documented under corresponding jira if applicable.
+
+Security Notes
+--------------
+
+*Fixed Security Issues*
+
+    Documented on earlier section
+
+*Known Security Issues*
+
+    None
+
+*Known Vulnerabilities in Used Modules*
+
+    None
+
+DCAE code has been formally scanned during build time using NexusIQ and all Critical vulnerabilities have been addressed, items that remain open have been assessed for risk and determined to be false positive. The DCAE open Critical security vulnerabilities and their risk assessment have been documented as part of the `project <https://wiki.onap.org/pages/viewpage.action?pageId=51282478>`_.
+
+Test Results
+------------
+
+ - `DCAE R9 Pairwise Test <https://wiki.onap.org/display/DW/DCAE+Pair+Wise+Testing+for+Istanbul+Release>`_
+ - `DCAE R9 Functional Test <https://wiki.onap.org/display/DW/DCAE+R9+Testplan>`_
+
+
+References
+----------
+
+For more information on the ONAP Honolulu release, please see:
+
+#. `ONAP Home Page`_
+#. `ONAP Documentation`_
+#. `ONAP Release Downloads`_
+#. `ONAP Wiki Page`_
+
+
+.. _`ONAP Home Page`: https://www.onap.org
+.. _`ONAP Wiki Page`: https://wiki.onap.org
+.. _`ONAP Documentation`: https://docs.onap.org
+.. _`ONAP Release Downloads`: https://git.onap.org
+
+Quick Links:
+
+        - `DCAE project page <https://wiki.onap.org/display/DW/Data+Collection+Analytics+and+Events+Project>`_
+        - `Passing Badge information for DCAE <https://bestpractices.coreinfrastructure.org/en/projects/1718>`_
+
 
 ..      =====================================
 ..      * * *    HONOLULU  MAINTENANCE  * * *