+heat_ims
+^^^^^^^^
+The IP Multimedia Subsystem or IP Multimedia Core Network Subsystem (IMS) is an
+architectural framework for delivering IP multimedia services.
+
+vIMS has been integrated in Functest to demonstrate the capability to deploy a
+relatively complex NFV scenario on the OPNFV platform. The deployment of a
+complete functional VNF allows the test of most of the essential functions
+needed for a NFV platform.
+
+The goal of this test suite consists of:
+
+* deploy a Clearwater vIMS (IP Multimedia Subsystem) VNF using
+ OpenStack Heat orchestrator based on a HOT template defined in `[17]`_
+* run suite of signaling tests on top of this VNF
+
+The Clearwater architecture is described as follows:
+
+.. figure:: ../../../images/clearwater-architecture-v2.png
+ :align: center
+ :alt: vIMS architecture