How to enable VoIP relaying on your Home Server with TURN Overview -------- The synapse Matrix Home Server supports integration with TURN server via the TURN server REST API (http://tools.ietf.org/html/draft-uberti-behave-turn-rest-00). This allows the Home Server to generate credentials that are valid for use on the TURN server through the use of a secret shared between the Home Server and the TURN server. This document described how to install coturn (https://code.google.com/p/coturn/) which also supports the TURN REST API, and integrate it with synapse. coturn Setup ============ 1. Check out coturn:: svn checkout http://coturn.googlecode.com/svn/trunk/ coturn cd coturn 2. Configure it:: ./configure You may need to install libevent2: if so, you should do so in the way recommended by your operating system. You can ignore warnings about lack of database support: a database is unnecessary for this purpose. 3. Build and install it:: make make install 4. Make a config file in /etc/turnserver.conf. You can customise a config file from turnserver.conf.default. The relevant lines, with example values, are:: lt-cred-mech use-auth-secret static-auth-secret=[your secret key here] realm=turn.myserver.org See turnserver.conf.default for explanations of the options. One way to generate the static-auth-secret is with pwgen:: pwgen -s 64 1 5. Ensure youe firewall allows traffic into the TURN server on the ports you've configured it to listen on (remember to allow both TCP and UDP if you've enabled both). 6. If you've configured coturn to support TLS/DTLS, generate or import your private key and certificate. 7. Start the turn server:: bin/turnserver -o synapse Setup ============= Your home server configuration file needs the following extra keys: 1. "turn_uris": This needs to be a comma-separated list of public-facing URIs for your TURN server to be given out to your clients. Add separate entries for each transport your TURN server supports. 2. "turn_shared_secret": This is the secret shared between your Home server and your TURN server, so you should set it to the same string you used in turnserver.conf. 3. "turn_user_lifetime": This is the amount of time credentials generated by your Home Server are valid for (in milliseconds). Shorter times offer less potential for abuse at the expense of increased traffic between web clients and your home server to refresh credentials. The TURN REST API specification recommends one day (86400000). As an example, here is the relevant section of the config file for matrix.org:: turn_uris: turn:turn.matrix.org:3478?transport=udp,turn:turn.matrix.org:3478?transport=tcp turn_shared_secret: n0t4ctuAllymatr1Xd0TorgSshar3d5ecret4obvIousreAsons turn_user_lifetime: 86400000 Now, restart synapse:: cd /where/you/run/synapse ./synctl restart ...and your Home Server now supports VoIP relaying!