Wrong location - have moved to Serviio Support & Help.
Firstly, this feature only works for the Pro version, or during the 15 day evaluation period. You can see what version you have in the Serviio Console, About Tab.
Have you tried Serviio's automatic port forwarding (UPNP) feature - on the Remote tab in the Serviio Console, tick "Automatically configure your router to allow Internet access" and press Save. You can press the Check Connectivity button and if you get a green tick then it is working. A red cross doesn't mean it isn't working, just means that Serviio cannot tell - I have found this has "been red" for me for quite a while, although my port is forwarded. To test, either look in your router web page (most routers will tell you if UPNP is forwarding a port) or use an external site to test eg.
http://www.checkmyports.net/ and enter port 23424.
If this doesn't work you will either need to check your router's UPNP settings and ensure that this function is on, or alternatively, you can manually forward the port. How to manually forward a port depends on your router - for yours see
http://portforward.com/english/routers/ ... tguide.htm.
Lastly, if either of the above are working (either UPNP or manually forwarding the port) and you still cannot get access from external locations, then it may not be the port. Check your firewall settings on the PC Serviio is loaded on. Good luck - come back with any issues.