Why can’t I access my Subsonic server from outside my home network (e.g. using cell data or on another WiFi network)?

Usually this is because your router has not been set up to forward the port that Subsonic uses. Most routers that support UPnP can be automatically configured by Subsonic. See the section below for more information about port forwarding.

However, sometimes Subsonic fails to setup the router, the router is not supported, or UPnP is disabled. In that case, please email iSub support at appstore@isubapp.com, contact me on Twitter at @iSubApp, or on Facebook at facebook.com/iSubApp and I’ll assist you in setting up the port forwarding manually.

What is a port and what is port forwarding?

Ports are like doors to your computer to allow other computers and smartphones to connect to specific applications. Your network also has the same set of doors.

Each port has a number between 1 and 65,535, which allows you to run more than one networked application on your computer at a time with one application per port.

The router that connects your computer to the internet automatically blocks these ports from the outside as a security measure, otherwise things that should only be accessible from inside your home would be accessible to anyone on the internet.

Port forwarding is the act of assigning one of your network's doors to a door on a specific device in your home network instead of blocking it. For example, to allow access to your Subsonic server from out side your network, you would tell the router that if someone tries to connect to port 4040, it should send that connection along to your computer's port 4040 (or any other port you choose). In other words, you would forward that port to the cooresponding port on your computer.

Subsonic tries to do this automatically. It talks to your router and sets up the forwarding so you don’t have to.

To enable this, log into your Subsonic web interface, go to the Settings > Network section, and make sure the top check box is checked. Then also make sure the second check box is checked, and choose an easy to remember domain name.

You can verify that it’s working by turning off WiFi on your device so that you are using cell data and trying to connect to the whatever-you-picked.subsonic.org URL in iSub or your device’s web browser. If it connects, then you’re good to go.

My port forwarding is definitely setup but I still can’t access my server from outside my home network.

The most common cause of this problem is that Subsonic somehow failed to foward the port automatically. See more information about that in the sections above.

If you still have issues connecting, please email iSub support at appstore@isubapp.com, contact me on Twitter at @iSubApp, or on Facebook at facebook.com/iSubApp and I’ll assist you in setting up the port forwarding manually.

Some Internet service providers block port 80, so if your Subsonic server is set to use port 80 and you have your port forwarding set up properly, the connection can still be blocked. If this is the case, try changing the port to 4040 and try to connect again. On Windows, you can change the port in the Subsonic preferences panel that is accessed by right clicking the Subsonic system tray icon. It should be 4040 by default

I can’t connect to my server, is the Subsonic service down?

Unlike streaming services, Subsonic, Airsonic, etc are standalone applications, so the connection is directly from your computer to your mobile device.

If you are having trouble connecting to your server, most likely either your internet is down at home, Subsonic is not running on your computer, or your computer is off.

If you are using a something-you-picked.subsonic.org URL then there is a slim chance that that server could be down, though it rarely happens.

If you want to be extra safe, you can sign up for a free No-IP account as a fail safe for those rare situations. Just remember that if you use No-IP, make sure to enable the the port 80 redirect option or you will need to put the Subsonic port after the URL like this: http://whatever-you-picked.no-ip.org:4040.

Why do Subsonic and iSub both cost money?

Subsonic and iSub are two independently created products.

It is always free to use Subsonic to stream music from your computer using the web interface. However, to use the Subsonic API that iSub and all other Subsonic clients use to connect, you must purchase a license from the Subsonic developer by navigating to the Subsonic Premium page.

Alternatively, if you use the AirSonic open source fork of Subsonic, all features including streaming to apps are 100% free.