Add glossary

Change-Id: Iaa5b7c6e59ef399e64f9e4d55fd4938514e55a07
diff --git a/glossary.rst b/glossary.rst
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--- /dev/null
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@@ -0,0 +1,11 @@
+Glossary
+========
+- DBUF: Software service responsible of implementing the UPF Downlink buffering feature
+- DDN: Downlink Data Notification
+- PCP: Programmable Control Plane team, now merged with PDP into SD-Fabric
+- PDP: Programmable Data Plane team, now merged with PCP into SD-Fabric
+- QFI: QoS Flow Identifier
+- TOST: Trellis, ONOS, Stratum and Tofino, the predecessor of SD-Fabric (now obsolete)
+- TNA: Tofino Native Architecture
+- UPF: 5G User Plane Function
+- UP4: P4 implementation of UPF of control-stack based on ONOS
diff --git a/index.rst b/index.rst
index 0434321..e6b0ada 100644
--- a/index.rst
+++ b/index.rst
@@ -33,6 +33,7 @@
    troubleshooting
    development
    testing
+   glossary
 
 .. toctree::
    :maxdepth: 2