diff --git a/docs/guides/onap-user/abbreviations.rst b/docs/guides/onap-user/abbreviations.rst
index 14644b6..89422fb 100644
--- a/docs/guides/onap-user/abbreviations.rst
+++ b/docs/guides/onap-user/abbreviations.rst
@@ -337,11 +337,8 @@
 |                                    | pedia.org/wiki/Network_function |
 |                                    | _virtualization>`__             |
 +------------------------------------+---------------------------------+
-| NFVI                               | `network functions              |
-|                                    | virtualization                  |
-|                                    | infrastructure <https://www.sdx |
-|                                    | central.com/nfv/definitions/nfv |
-|                                    | -mano/>`__                      |
+| NFVI                               | Network Functions               |
+|                                    | Virtualization Infrastructure   |
 +------------------------------------+---------------------------------+
 | NOD                                | Network On Demand               |
 +------------------------------------+---------------------------------+
@@ -379,9 +376,7 @@
 | OMSA                               | ONAP Microservice Architecture  |
 +------------------------------------+---------------------------------+
 | ONAP                               | `Open Network Automation        |
-|                                    | Platform <https://wiki.onap.org |
-|                                    | /pages/viewpage.action?pageId=1 |
-|                                    | 015843>`__                      |
+|                                    | Platform`                       |
 +------------------------------------+---------------------------------+
 | OOF                                | ONAP Optimization Framework     |
 +------------------------------------+---------------------------------+
@@ -394,9 +389,8 @@
 +------------------------------------+---------------------------------+
 | OpenStack                          | A cloud operating system        |
 +------------------------------------+---------------------------------+
-| OPNFV                              | `Open Platform for NFV          |
-|                                    | Project <https://www.sdxcentral |
-|                                    | .com/nfv/definitions/opnfv/>`__ |
+| OPNFV                              | Open Platform for NFV           |
+|                                    | Project                         |
 +------------------------------------+---------------------------------+
 | Originato                          | MMSC Any Non-AT&T MMSC that     |
 |                                    | originally sent the request to  |
@@ -600,12 +594,7 @@
 |                                    | 3+Clean+Version+with+IFA011+v2. |
 |                                    | 5.1>`__                         |
 +------------------------------------+---------------------------------+
-| VES                                | `Virtual function               |
-|                                    | EventStream <https://wiki.opnfv |
-|                                    | .org/download/attachments/68193 |
-|                                    | 29/OPNVF%20VES.pptx?version=4&m |
-|                                    | odificationDate=1466395653000&a |
-|                                    | pi=v2>`__                       |
+| VES                                | Virtual function EventStream    |
 +------------------------------------+---------------------------------+
 | vF                                 | Virtual Firewall (an example    |
 |                                    | VNF)                            |
diff --git a/docs/guides/onap-user/connect.rst b/docs/guides/onap-user/connect.rst
index 6ae69bf..c7bb341 100644
--- a/docs/guides/onap-user/connect.rst
+++ b/docs/guides/onap-user/connect.rst
@@ -34,7 +34,7 @@
 By right-clicking on an element, an action menu opens. The menu allows
 to mount, unmount, view the details, edit and remove the element.
 Additionally, it links to several applications like
-`Fault <pnfFault.html>`__ and `Configure <pnfConfig.html>`__, which will
+:doc:`Fault <pnfFault>` and :doc:`Configure <pnfConfig>`, which will
 be filtered to display information relevant to the selected element.
 
 Connection Status Log
diff --git a/docs/guides/onap-user/home.rst b/docs/guides/onap-user/home.rst
index a756d81..668db4d 100644
--- a/docs/guides/onap-user/home.rst
+++ b/docs/guides/onap-user/home.rst
@@ -14,7 +14,7 @@
 
 | SDN-R is integrated into ONAP. Therefore it is interfacing with PNFs
   and VNFs and with other ONAP components, such as A&AI, DCAE and SO.
-| `See abbreviations <abbreviations>`__
+| :doc:`See abbreviations <abbreviations>`
 
 .. figure:: ./ONAP-SDN-R.png
    :alt: SDN-R in ONAP
diff --git a/docs/guides/onap-user/networkMap.rst b/docs/guides/onap-user/networkMap.rst
index 6dc4fb9..5efc671 100644
--- a/docs/guides/onap-user/networkMap.rst
+++ b/docs/guides/onap-user/networkMap.rst
@@ -64,7 +64,7 @@
 clicking on a link, the given link is loaded into details.
 
 If a link of type ‘microwave’ is selected, the ‘calculate link’ button
-is available, which opens the `Link Calculator <linkCalculator.html>`__
+is available, which opens the :doc:`Link Calculator <linkCalculator>`
 in a new tab or page.
 
 Just like the map, the details panel updates the URL if data is loaded.
diff --git a/docs/guides/onap-user/sdnr_Docker_Image_configuration.rst b/docs/guides/onap-user/sdnr_Docker_Image_configuration.rst
index 5297a09..7835fba 100644
--- a/docs/guides/onap-user/sdnr_Docker_Image_configuration.rst
+++ b/docs/guides/onap-user/sdnr_Docker_Image_configuration.rst
@@ -46,7 +46,7 @@
 |                  |                     |                                                                                                                         |
 |                  |                     | Devicemanager configuration is provided via *$ODL\_HOME/etc/devicemanager.properties*                                   |
 |                  |                     |                                                                                                                         |
-|                  |                     | See  `SDN-R WT Service Configuration parameters <sdnr_WT_Service_Configuration_parameters.html>`__			   |
+|                  |                     | See :doc:`SDN-R WT Service Configuration parameters <sdnr_WT_Service_Configuration_parameters>`                         |
 +------------------+---------------------+-------------------------------------------------------------------------------------------------------------------------+
 | SDNRNORTHBOUND   | true\|\ **false**   | Set true to activate sdnr oofpci service.                                                                               |
 +------------------+---------------------+-------------------------------------------------------------------------------------------------------------------------+
diff --git a/docs/guides/onap-user/sdnr_WT_Service_Configuration_parameters.rst b/docs/guides/onap-user/sdnr_WT_Service_Configuration_parameters.rst
index a27e511..767af4a 100644
--- a/docs/guides/onap-user/sdnr_WT_Service_Configuration_parameters.rst
+++ b/docs/guides/onap-user/sdnr_WT_Service_Configuration_parameters.rst
@@ -14,7 +14,7 @@
    -  `devicemonitor <#SDN-RWTServiceConfigurationparameters-d>`__
 
 Backgrounds regarding the container inter structure is described
-in \ `SDN-R Docker Image configuration <sdnr_Docker_Image_configuration.html>`__.
+in \ :doc:`SDN-R Docker Image configuration <sdnr_Docker_Image_configuration>`.
 
 The configuration information of sdnr wireless transport parameters are
 in a single file.
diff --git a/docs/tox.ini b/docs/tox.ini
index 7a8b689..8e5325e 100644
--- a/docs/tox.ini
+++ b/docs/tox.ini
@@ -1,6 +1,6 @@
 [tox]
 minversion = 1.6
-envlist = docs,
+envlist = docs,linkcheck
 skipsdist = true
 
 [testenv:docs]
@@ -11,18 +11,15 @@
     -chttps://git.onap.org/doc/plain/etc/upper-constraints.onap.txt
 commands =
     sphinx-build -W -b html -n -d {envtmpdir}/doctrees ./ {toxinidir}/_build/html
-    echo "Generated docs available in {toxinidir}/_build/html"
-whitelist_externals =
-    echo
-    git
-    sh
 
 [testenv:docs-linkcheck]
 basepython = python3.8
-#deps = -r{toxinidir}/requirements-docs.txt
-commands = echo "Link Checking not enforced"
-#commands = sphinx-build -b -W linkcheck -d {envtmpdir}/doctrees ./ {toxinidir}/_build/linkcheck
-whitelist_externals = echo
+deps =
+    -r{toxinidir}/requirements-docs.txt
+    -chttps://raw.githubusercontent.com/openstack/requirements/stable/yoga/upper-constraints.txt
+    -chttps://git.onap.org/doc/plain/etc/upper-constraints.onap.txt?h=master
+commands =
+    sphinx-build -W -q -b linkcheck -d {envtmpdir}/doctrees {toxinidir} {toxinidir}/_build/linkcheck
 
 [testenv:docs-spellcheck]
 basepython = python3.8