I connect from my N900 to DVBViewer on my home pc. Problem is that when I connect using my mobile broadband connection the IP of connection changes every time I restart the connection. I have to open port for DVBViewer on my router and as IP of N900 side changes I no longer get in.

Is there any way to avoid this, using some sort of proxy or something?

Is your N900 or you home PC changing IP?

my N900, with the mobile broadband

Since you mentioned Router, I'm going to assume your N900 connects to the internet through it, but every time you connect, the N900 recieves a different IP address (192.168.1.X). For my particular router (a NetComm), I am able to set static IP addresses to specific computers and devices attached to my router through an advanced tab -> Lan Clients. Is there anything similar to that in your router? What model is it?

If I understood you wrong, can you please offer us more information about what connects to what etc

Yes, there is. You can subscribe to a proxy service with static IP, set up a tunnel and access your home computer via proxy. To your home it would then appear as if you have the same IP every time.

Of course, for this sort of connection to work you'd need a fast proxy service, and I somehow don't think the average proxy service is fast enough to stream material. But technically, this is a way to avoid changing IP.

One specific way to do this would be to order a VPS service from Tocici here. If I read that page correctly, the cheapest package with a shared IP is...? Edit: I read it wrong. $3/mo, I guess.

Volt got it. I connect with my mobile internet N900 and want my home router to see the same IP every time

then you can both setup your own proxy/tunnel (which could require some tech skill) or subscribe to a proxying service.

Surely your router has nothing to do with the external IP of your phone's data connection, just your internal WIFI IP?

If your router supports the Static IP based on the Computer Name, you should be able to assign a static IP from your router.

Sample Router that supports: D-LINK DIR-655

You dont need the router to sign the static IP address for the N900. This can be done on the N900 itself.

Correct me if I'm wrong, but this is not the issue in this case. MRP is not connecting to the router with his phone, he is using mobile broadband which gives him a different IP every so often. What he needs is a way to stop the IP of his N900 changing when not connected via the router.