Merge branch 'develop' into babolivier/mark_unread

1 files changed, 52 insertions, 16 deletions

diff --git a/docs/turn-howto.md b/docs/turn-howto.md
index 4a983621e5..d4a726be66 100644
--- a/docs/turn-howto.md
+++ b/docs/turn-howto.md
@@ -11,7 +11,14 @@ TURN server.
 
 The following sections describe how to install [coturn](<https://github.com/coturn/coturn>) (which implements the TURN REST API) and integrate it with synapse.
 
-## `coturn` Setup
+## Requirements
+
+For TURN relaying with `coturn` to work, it must be hosted on a server/endpoint with a public IP.
+
+Hosting TURN behind a NAT (even with appropriate port forwarding) is known to cause issues
+and to often not work.
+
+## `coturn` setup
 
 ### Initial installation
 
@@ -19,7 +26,13 @@ The TURN daemon `coturn` is available from a variety of sources such as native p
 
 #### Debian installation
 
-    # apt install coturn
+Just install the debian package:
+
+```sh
+apt install coturn
+```
+
+This will install and start a systemd service called `coturn`.
 
 #### Source installation
 
@@ -39,6 +52,8 @@ The TURN daemon `coturn` is available from a variety of sources such as native p
         make
         make install
 
+### Configuration
+
 1.  Create or edit the config file in `/etc/turnserver.conf`. The relevant
     lines, with example values, are:
 
@@ -54,38 +69,52 @@ The TURN daemon `coturn` is available from a variety of sources such as native p
 1.  Consider your security settings. TURN lets users request a relay which will
     connect to arbitrary IP addresses and ports. The following configuration is
     suggested as a minimum starting point:
-    
+
         # VoIP traffic is all UDP. There is no reason to let users connect to arbitrary TCP endpoints via the relay.
         no-tcp-relay
-        
+
         # don't let the relay ever try to connect to private IP address ranges within your network (if any)
         # given the turn server is likely behind your firewall, remember to include any privileged public IPs too.
         denied-peer-ip=10.0.0.0-10.255.255.255
         denied-peer-ip=192.168.0.0-192.168.255.255
         denied-peer-ip=172.16.0.0-172.31.255.255
-        
+
         # special case the turn server itself so that client->TURN->TURN->client flows work
         allowed-peer-ip=10.0.0.1
-        
+
         # consider whether you want to limit the quota of relayed streams per user (or total) to avoid risk of DoS.
         user-quota=12 # 4 streams per video call, so 12 streams = 3 simultaneous relayed calls per user.
         total-quota=1200
 
-    Ideally coturn should refuse to relay traffic which isn't SRTP; see
-    <https://github.com/matrix-org/synapse/issues/2009>
+1.  Also consider supporting TLS/DTLS. To do this, add the following settings
+    to `turnserver.conf`:
+
+        # TLS certificates, including intermediate certs.
+        # For Let's Encrypt certificates, use `fullchain.pem` here.
+        cert=/path/to/fullchain.pem
+
+        # TLS private key file
+        pkey=/path/to/privkey.pem
 
 1.  Ensure your firewall allows traffic into the TURN server on the ports
-    you've configured it to listen on (remember to allow both TCP and UDP TURN
-    traffic)
+    you've configured it to listen on (By default: 3478 and 5349 for the TURN(s)
+    traffic (remember to allow both TCP and UDP traffic), and ports 49152-65535
+    for the UDP relay.)
+
+1.  (Re)start the turn server:
 
-1.  If you've configured coturn to support TLS/DTLS, generate or import your
-    private key and certificate.
+    * If you used the Debian package (or have set up a systemd unit yourself):
+      ```sh
+      systemctl restart coturn
+      ```
 
-1.  Start the turn server:
+    * If you installed from source:
 
-         bin/turnserver -o
+      ```sh
+      bin/turnserver -o
+      ```
 
-## synapse Setup
+## Synapse setup
 
 Your home server configuration file needs the following extra keys:
 
@@ -111,13 +140,20 @@ Your home server configuration file needs the following extra keys:
 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_shared_secret: "n0t4ctuAllymatr1Xd0TorgSshar3d5ecret4obvIousreAsons"
     turn_user_lifetime: 86400000
     turn_allow_guests: True
 
 After updating the homeserver configuration, you must restart synapse:
 
+  * If you use synctl:
+    ```sh
     cd /where/you/run/synapse
     ./synctl restart
+    ```
+  * If you use systemd:
+    ```
+    systemctl restart synapse.service
+    ```
 
 ..and your Home Server now supports VoIP relaying!