HLS(HttpLiveStreaming) vs RTP（Real-time Transport Protocol) on UDP for mobile P2P?
I'm testing Audio/Video P2P connection between mobile devices.
Studying WebRTC, I've noticed NAT traversal(uses STUN server) and UDP-hole-punching is the key to make P2P possible.
On the other hand, I've noticed HLS(HttpLiveStreaming) on iOS devices is very optimized for A/V live streaming, and widely available even with Android4.x(3.x unstable)
So, here is my question if I use HLS for mobile P2P:
a) HLS is a protocol on TCP(HTTP) not UDP, so isn't there a performance drawback?
See: TCP vs UDP on video stream
b) How about NAT traversal? Will it be easier since HLS is HTTP(port:80)? I have read wikipedia http://en.wikipedia.org/wiki/HTTP_Live_Streaming
Since its requests use only standard HTTP transactions, HTTP Live Streaming is capable of traversing any firewall or proxy server that lets through standard HTTP traffic, unlike UDP-based protocols such as RTP. This also allows content to be delivered over widely available CDNs.
c) How about android device compatibility? Is there a lot of problems to invoke StreamingLive distribution?
Thanks.
Answer
The reason why firewalls are not an issue for HLS is that it's a client-server protocol where all requests are done via HTTP on port 80. If you are implementing a P2P application, you won't be able to attach it to a port below 1024 unless you have root privileges.
This means that exchanging data via HLS (port 80) won't work for P2P. Unless you have a translation server in the middle, which defeats the purpose of P2P.