Flexisip is a complete, modular and scalable SIP server suite written in C++17, comprising proxy, presence and conference functions. It also includes a push notification service, to deliver SIP incoming calls or text messages on mobile device platforms where push notifications are required to receive information when the app is not active in the foreground.

Flexisip instances can be deployed on server machines to run a SIP VoIP service. The free linphone.org SIP service has run on Flexisip since 2011, and enables Linphone users to create SIP addresses in order to connect with each other.

It can also be embedded and run perfectly on small hardware systems.

License

Flexisip is dual licensed, and can be licensed and distributed:

under a GNU Affero GPLv3 license for free (see COPYING file for details)
under a proprietary license, for closed source projects. Contact Belledonne Communications for any question about costs and services.

Documentation

Dependencies

Dependency	Description	Mandatory	Enabled by default
OpenSSL	TLS stack.	X
LibNgHttp2	HTTP2 stack.	X
libsrtp2	Secure RTP (SRTP) and UST Reference Implementations	X
SQLite3	Library for handling SQlite3 file	X
libmysql-client	Client library for MySQL database.	X
Hiredis	Redis DB client library, used for Registrar DB and communications between Flexisip instances of a same cluster. (-DENABLE_REDIS=YES)		X
Protobuf	Needed for migration from legacy registrar database format. (-DENABLE_PROTOBUF=YES)		X
NetSNMP	SNMP library, used for SNMP support. (-DENABME_SNMP=YES)		X
XercesC	XML parser. (-DENABLE_PRESENCE=YES)		X
jsoncpp	JSON parsing and writing (-DENABLE_B2BUA=YES)		X

Compilation

Required build tools

C and C++ compiler. GCC and Clang are supported as long as they are recent enough for building C++14 code. On Redhat/CentOS 7, we recommend installing gcc-7 from https://www.softwarecollections.org/en/scls/rhscl/devtoolset-7/ . The default gcc-4.8 is not sufficient.
CMake >= 3.13
make or Ninja
Python >= 3
Doxygen
Git

Building Flexisip with CMake

Create a build directory and configure the project:

mkdir ./build
cmake -S . -B ./build
make -C ./build -j<njobs>

Check CMakeLists.txt to know the list of the available options and their default value. To change an option, you just need to invoke CMake again by specifying the option you need to change only. For instance, to disable the presence server feature:

cmake ./build -DENABLE_PRESENCE=OFF
make -C ./build -j<njobs>

You may also use ccmake or cmake-gui utilities to configure the project interactively:

ccmake ./build
make -C ./build -j<njobs>

Building RPM or DEB packages

This procedure will make a unique RPM package containing Flexisip and all its dependencies and the according package for debug symbols.

The following options are relevant for packaging:


`CMAKE_INSTALL_PREFIX`	The prefix where the package will installed the files.
`SYSCONF_INSTALL_DIR`	Where Flexisip expect to find its default configuration directory.
`CMAKE_BUILD_TYPE`	Set this to “RelWithDebInfo” to have debug symbols in the debuginfo package.
`CPACK_GENERATOR`	Select the kind of package. “RPM” or “DEB”.

cmake ./build -DCMAKE_INSTALL_PREFIX=/opt/belledonne-communications -DCMAKE_BUILD_TYPE=RelWithDebInfo -DSYSCONF_INSTALL_DIR=/etc -DCPACK_GENERATOR=RPM
make -C ./build -j<njobs> package

The packages are now available in ./build directory.

Docker

A docker image can be build from sources with command:

docker build -t flexisip --build-arg='njobs=<njobs>' -f docker/flex-from-src .

Nix ❄️

Flexisip can also be compiled with Nix. You can obtain a development shell with: (from the root of the repository)

nix-shell

Or with Flakes enabled:

nix develop

Nix makes it easier to have a reproducible development environment on any Linux distribution, and doesn't interfere with other installed tooling. It is just an additional, optional way to build flexisip.

Example build commands:

CC=gcc CXX=g++ BUILD_DIR_NAME="build" cmake -DCMAKE_EXPORT_COMPILE_COMMANDS=1 -S . -B ./$BUILD_DIR_NAME -G "Ninja" -DCMAKE_BUILD_TYPE=Debug -DCMAKE_INSTALL_PREFIX="$PWD/$BUILD_DIR_NAME/install" -DENABLE_UNIT_TESTS=ON -DENABLE_STRICT_LINPHONESDK=OFF -DINTERNAL_JSONCPP=OFF
cd build
clear && cmake --build . --target install && LSAN_OPTIONS="suppressions=../sanitizer_ignore.txt" bin/flexisip_tester --resource-dir "../tester/" --verbose

Note to maintainers

At the exception of shell.nix, .nix files should live inside the nix/ folder.

All .nix files should be formatted with nixpkgs-fmt.

Configuration

Flexisip needs a configuration file to run correctly. Use ./flexisip --dump-all-default > flexisip.conf to make a documented default configuration file.

Developer notes

With sofia-sip, you have the choice between msg_dup() and msg_copy(), sip_from_dup() and sip_from_copy(), etc. The difference isn't well documented in sofia-sip documentation but it is important to understand that:

*_dup() makes a copy of the structure plus all included strings inside. (deep copy)
*_copy() just makes a copy of the structure, not the strings pointed by it. (shallow copy) These functions are dangerous; use *_dup() versions in doubt.

Your build is broken but you don't see how that's your fault? (E.g. trying to compile a file you removed, and you've double-checked it is not referenced anywhere in the source code anymore) Try reconfiguring and regenerating. (With e.g. ccmake)

lifetyper/flexisip