diff --git a/readme.md b/readme.md
index 011cc1ce..ba62b802 100644
--- a/readme.md
+++ b/readme.md
@@ -37,8 +37,14 @@ E.g. https://internal.ip.of.this.server:8080<br>
 If your server has port 80 and 8443 open and you point a domain to your server, you can get a valid certificate automatially by opening the Nextcloud AIO Interface via:<br>
 https://your-domain-that-points-to-this-server.tld:8443
 
-Explanation of used ports:
+### Which ports are mandatory to be open?
+Only those (if you acces the Mastercontainer Interface internally via port 8080):
+- `443/TCP` for the Nextcloud container
+- `3478/TCP` and `3478/UPD` for the Talk container
 
-- `80`: redirects to Nextcloud (HTTP) (is used for getting the certificate via ACME http-challenge for mastercontainer)
-- `8080`: Master Container Interface with self-signed certificate (HTTPS) (works always, also if only access via IP-address is possible, e.g. `https://internal.ip.address:8080/`)
-- `8443`: Master Container Interface with valid automatic certificate via Let's Encrypt! (HTTPS) (Only works if you access the container via a public domain, e.g. `https://public.domain.com:8443/` and not via IP-address.)
+### Explanation of used ports:
+- `8080/TCP`: Mastercontainer Interface with self-signed certificate (works always, also if only access via IP-address is possible, e.g. `https://internal.ip.address:8080/`)
+- `80/TCP`: redirects to Nextcloud (is used for getting the certificate via ACME http-challenge for the Mastercontainer)
+- `8443/TCP`: Mastercontainer Interface with valid certificate (only works if port 80 and 8443 are open and you point a domain to your server. It generates a valid certificate then automatically and access via e.g. `https://public.domain.com:8443/` is possible.)
+- `443/TCP`: will be used by the Nextcloud container later on and needs to be open
+- `3478/TCP` and `3478/UPD`: will be used by the Turnserver inside the Talk container and needs to be open