diff --git a/matrix/coturn/README.md b/matrix/coturn/README.md
index 2dbfc81..965b7c9 100644
--- a/matrix/coturn/README.md
+++ b/matrix/coturn/README.md
@@ -71,7 +71,7 @@ This assumes you've already setup and started nginx (see [nginx](../nginx)).
 Of course, when this certificate is renewed, coturn must be restarted!
 
 
-# Configurationfile
+# Configuration {#configuration}
 
 Synapse's documentation gives a reasonable [default
 config](https://element-hq.github.io/synapse/latest/setup/turn/coturn.html).
diff --git a/matrix/firewall/README.md b/matrix/firewall/README.md
index 7d0f09f..320e435 100644
--- a/matrix/firewall/README.md
+++ b/matrix/firewall/README.md
@@ -6,8 +6,13 @@ is -of course- very important.
 First idea: the ports that need to be opened are:
 
 
-| Port(s) / range | Protocol | Application |
-| :--: | :--: | :-- |
-| 80, 443 | TCP | Reverse proxy |
-| 8443 | TCP | Synapse, federation |
+| Port(s) / range | IP version | Protocol | Application            |
+| :-------------: | :--------: | :------: | :--------------------- |
+| 80, 443         | IPv4/IPv6  | TCP      | nginx, reverse proxy   |
+| 8443            | IPv4/IPv6  | TCP      | nginx, federation      |
+| 3478, 5349      | IPv4       | TCP/UDP  | coturn, TURN           |
+| 50000-60000     | IPv4       | UDP      | coturn, TURN           |
 
+
+The ports necessary for TURN depend very much on the specific [configuration
+of coturn](../coturn#configuration).