- Readme for PGM library installation

git-svn-id: http://svn.eurecom.fr/openair4G/trunk@4017 818b1a75-f10b-46b9-bf7c-635c3b92a50f

openair1/SIMULATION/ETH_TRANSPORT/README.txt

+For reliable UDP multicast, the libpgm-dev should be installed on the machines,
+otherwise the old multicast method using simply UDP will be used, resulting in
+packet loss and unexpected behaviour of oaisim.
+
+To compile OAI with PGM:
+
+For Ubuntu 12.04 and earliers:
+    sudo apt-get install libpgm-dev
+    is sufficient
+
+For Ubuntu older than 12.04:
+
+wget http://openpgm.googlecode.com/files/libpgm-5.1.118.tar.gz
+tar xvf libpgm-5.1.118.tar.gz
+cd libpgm-5.1.118/openpgm/pgm
+./configure
+make
+sudo make install
+
+We have to clean oaisim compilation and re-compile