rtmp2rtmpt can be used as a transparent proxy (by using a REDIRECT rule in netfilter) or it can alternatively forward data to a single server. RTMPT encapsulates RTMP data in HTTP and therefore allows RTMP connections to traverse HTTP-only proxies.
There are a couple of use cases for this program:
- The implementation of RTMPT in the Linux version of Adobe's Flash Player 10.1 contains a bug which renders it unusable (https://bugs.adobe.com/jira/browse/FP-4797). The net effect of this bug is that the HTTP headers sent by the Flash Player will grow indefinitely in each subsequent request. Eventually the headers will become so large that they will be rejected by either the remote server or an intermediary proxy, resulting in a premature termination of video playback.
- Some flash applications are hard-coded so that they only attempt to establish an RTMP connection and do not fall back to RTMPT if the connection attempt fails.
In both cases, users which can only access the remote server via a HTTP proxy (and are behind a firewall which blocks outgoing connections on port 1935) are left with no way access RTMP streams. This is where rtmp2rtmpt is useful.