+PDCP Flow Diagram
+~~~~~~~~~~~~~~~~~
+
+Based on 3GPP TS 36.323 Evolved Universal Terrestrial Radio Access (E-UTRA);
+Packet Data Convergence Protocol (PDCP) specification
+
+.. code-block:: c
+
+ Transmitting PDCP Entity Receiving PDCP Entity
+ | ^
+ | +-----------|-----------+
+ V | In order delivery and |
+ +---------|----------+ | Duplicate detection |
+ | Sequence Numbering | | (Data Plane only) |
+ +---------|----------+ +-----------|-----------+
+ | |
+ +---------|----------+ +-----------|----------+
+ | Header Compression*| | Header Decompression*|
+ | (Data-Plane only) | | (Data Plane only) |
+ +---------|----------+ +-----------|----------+
+ | |
+ +---------|-----------+ +-----------|----------+
+ | Integrity Protection| |Integrity Verification|
+ | (Control Plane only)| | (Control Plane only) |
+ +---------|-----------+ +-----------|----------+
+ +---------|-----------+ +----------|----------+
+ | Ciphering | | Deciphering |
+ +---------|-----------+ +----------|----------+
+ +---------|-----------+ +----------|----------+
+ | Add PDCP header | | Remove PDCP Header |
+ +---------|-----------+ +----------|----------+
+ | |
+ +----------------->>----------------+
+
+
+.. note::
+
+ * Header Compression and decompression are not supported currently.
+
+Just like IPsec, in case of PDCP also header addition/deletion, cipher/
+de-cipher, integrity protection/verification is done based on the action
+type chosen.
+