Firewall comparaison into RTP unicast and HTTP methods ?

[NeoKoD]

Hi !

I streaming video for distant peoples over Internet, actually i use the HTTP method and set a port forwarding of my firewall on my machine.
For distants restrictive firewalls i use the port 8080.

If i want streaming over RTP Unicast ( i have the IP address of clients ) i suppose i don't need to set port forwarding isn't it ?
But if the distants people are behind a firewall,
they have to configure their firewall for port forwarding ?

What's the more efficient bandwidth between RTP unicast and HTTTP methods ?

Thanks