--- /dev/null
+/*****************************************************************************
+# *
+# Copyright 2019 AT&T Intellectual Property *
+# Copyright 2019 Nokia *
+# *
+# Licensed under the Apache License, Version 2.0 (the "License"); *
+# you may not use this file except in compliance with the License. *
+# You may obtain a copy of the License at *
+# *
+# http://www.apache.org/licenses/LICENSE-2.0 *
+# *
+# Unless required by applicable law or agreed to in writing, software *
+# distributed under the License is distributed on an "AS IS" BASIS, *
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. *
+# See the License for the specific language governing permissions and *
+# limitations under the License. *
+# *
+******************************************************************************/
+
+# INSTALLATION
+ * Tested environment: Ubuntu 16.04
+ * Install dependencies
+ $ sudo apt-get update
+ $ sudo apt-get install -y
+ build-essential
+ git
+ cmake
+ libsctp-dev
+ lksctp-tools
+ autoconf
+ automake
+ libtool
+ bison
+ flex
+ libboost-all-dev
+ $ sudo apt-get clean
+
+ ## Build
+ $ ./build_e2sim
+
+# SET ENVIRONMENT VARIABLE
+ Add this line to `~/.bashrc`
+ $ export E2SIM_DIR=<your e2sim directory>
+
+# RUN E2SIM
+ $ cd $E2SIM_DIR/build/
+ $ ./e2agent [SERVER IP] [PORT]
+
+ By default, SERVER IP = 127.0.0.1, PORT = 36422 (X2AP Port)
+
+# DOCKER
+ Note: The commands in this section must be run from $E2SIM_DIR
+
+ * Build docker image
+ $ ./build_docker
+
+ ## Run docker container
+ $ sudo docker run --rm --net host -it e2agent sh -c "./build/e2agent [SERVER IP] [PORT]"
+
+# SUPPORTED MESSAGE FLOWS (Last updated May 24, 2019)
+
+- X2 SETUP REQUEST (RIC -> RAN)
+- X2 SETUP RESPONSE (RAN -> RIC)
+
+- ENDC X2 SETUP REQUEST (RIC -> RAN)
+- ENDC X2 SETUP RESPONSE (RAN -> RIC)
+
+- RIC SUBSCRIPTION REQUEST (RIC -> RAN)
+- RIC SUBSCRIPTION RESPONSE (RAN -> RIC)
+- RIC SUBSCRIPTION FAILURE (RAN -> RIC)
+
+
+# Change logs:
+ 03/12/2019: currently supports sending and receiving X2 SETUP messages
+ 05/21/2019: add support for ENDC X2 SETUP
+ no longer use asn1c
+ all X2AP and E2AP messages are encapsulated into E2AP-PDU
+ 05/24/2019: add support for RIC SUBSCRIPTION REQUEST, RESPONSE, and FAILURE