SRTP Protocol
=============

This document describe the VPP SRTP (Secure Real-time Transport
Protocol) implementation libsrtp2 based SRTP transport protocol
implementation.

Maturity level
--------------

Experimental

Quickstart
----------

1. Install libsrtp2-dev. On debian based OS:

::

   sudo apt get install libsrtp2-dev

2. Build vpp

::

   make build

3. Test protocol using vcl test server and client. On server side, start
   vpp and server app:

::

   export VT_PATH=$WS/build-root/build-vpp_debug-native/vpp/bin
   $VT_PATH/vcl_test_server 1234 -p srtp

On client side:

::

   export VT_PATH=$WS/build-root/build-vpp_debug-native/vpp/bin
   $VT_PATH/vcl_test_client <server-ip> 1234 -U -X -S -N 10000 -T 128 -p srtp

Custom libsrtp2 build
---------------------

1. Create ``build/external/packages/srtp.mk`` with following example
   contents:

::

   srtp_version := 2.3.0
   srtp_tarball := srtp_$(srtp_version).tar.gz
   srtp_tarball_md5sum := da38ee5d9c31be212a12964c22d7f795
   srtp_tarball_strip_dirs := 1
   srtp_url := https://github.com/cisco/libsrtp/archive/v$(srtp_version).tar.gz

   define  srtp_build_cmds
       @cd $(srtp_build_dir) && \
           $(CMAKE) -DCMAKE_INSTALL_PREFIX:PATH=$(srtp_install_dir)    \
           -DCMAKE_C_FLAGS='-fPIC -fvisibility=hidden'  $(srtp_src_dir) > $(srtp_build_log)
       @$(MAKE) $(MAKE_ARGS) -C $(srtp_build_dir) > $(srtp_build_log)
   endef

   define  srtp_config_cmds
       @true
   endef

   define  srtp_install_cmds
       @$(MAKE) $(MAKE_ARGS) -C $(srtp_build_dir) install > $(srtp_install_log)
   endef


   $(eval $(call package,srtp))

2. Include ``srtp.mk`` in ``build/external/Makefile`` and add to install
   target.

3. Rebuild external dependencies:

::

   make install-ext-deps