RTMP Direct mode sends the RTMP protocol directly from the LiveU Solo unit. This means the unit cannot bond multiple connections, as RTMP does not support bonding. The alternative option is to send LiveU Reliable Transport protocol, or LRT, which does allow bonding.
Why would you choose to use RTMP Direct mode then? There are a few specific use cases where it can be the right choice over LRT:
- LRT is streamed to LiveU's cloud service, which repackages it as RTMP - this is hosted in the cloud. If you have a need to stream over only private bandwidth, and you have entered a private ingress point into your settings in the configuration portal, you want to use RTMP Direct mode.
- LRT, to add the resiliency and bonding that it does, does add some latency to the stream. If you need the absolute lowest latency, RTMP Direct mode may be what you need. But, you do trade resiliency for this lower latency - in most common use cases, you will find the latency added by LRT to be small and worth the additional resilience - particularly when using cellular modems.