Testing Wowza's Real-Time Streaming at Scale
With all the hype surrounding low latency, Streaming Media contributing editor Tim Siglin took a look at the claims Wowza is making around its new real-time streaming at scale offering.
Siglin, a veteran consultant and reviewer with more than three decades of testing interactive video, streaming, and videoconferencing hardware and software, now provides test validation as part of his role as founding executive director at the not-for-profit Help Me Stream Research Foundation. Wowza approached Help Me Stream about reviewing its Wowza Streaming Cloud addition, known as Real-Time Streaming at Scale, a few weeks before general availability (GA). [Disclosure: Streaming Media editor and VP Eric Schumacher-Rasmussen is volunteer chairman of Help Me Stream Research Foundation.]
The results of his detailed review, including high marks and still-to-be-addressed issues, can be found on the Wowza blog. While Wowza reviewed Siglin's results, the testing was done at Help Me Stream's testing facility in Kingsport, Tennessee and the company did not influence the testing environment.
Wowza's contention is that there are numerous users looking to achieve real-time deliver to audiences above the typical Zoom-based dozen or even a hundred viewers.
"In a recent Wowza survey, 57% of respondents indicated that they desired sub-one-second latency for their live streaming workflows," Wowza's Jon Duncan wrote in the official GA announcement from Wowza, noting that the survey responses indicated a need for a solution that would scale to more than 300 viewers. "Despite this, most are still experiencing a delay in the 3-45 second range."
"We designed our Real-Time Streaming at Scale feature to answer these needs, thereby ensuring a time-synchronized experience across the globe," wrote Duncan.
Siglin's testing looked at synchronization and latency, which are two different areas of concern for StreamingMedia.com readers. Some are interested in full synchronization of live streams across multiple viewers, even if it means a short delay, while others are more concerned about the lowest possible latency.
With a background in videoconferencing, before entering the streaming space 24 years ago, Siglin's experience testing ultra low latency (less than 250 milliseconds glass-to-glass) served well in testing Wowza's solution.
He'd also written an article for StreamingMedia.com several years ago titled "Latency Sucks! So Which Companies Are Creating a Solution?" that quoted Wowza's then-streaming evangelist, Chris Knowlton, on the need to balance between RTMP streams—a mainstay in the streaming industry, even though it's decades old—with newer, more interactive low-latency protocols.
Siglin notes that RTMP has found new uses, including for open-source video mixing and streaming tools like OBS, a version of which Wowza is also offering for it's Real-Time Streaming at Scale customers.
"We're not only using RTMP quite a bit longer after its initial required server has been deprecated (think Flash Media Server), but the streaming industry is finding new uses for RTMP," said Siglin in his review. "One of those is RTMP's ability to generate low-latency encodes that can now be scaled by solutions like Wowza's that the original RTMP streaming servers were incapable of performing."
The version of OBS that Wowza is offering can either generate a WebRTC stream or an RTMP stream, and Siglin noted in his review that WebRTC did offer a lower overall latency on the Help Me Stream Research test bench.
"Our cellular data playback test exhibited slightly lower latencies than the playback via a WiFi access point attached to a cable modem," said Siglin. "But the difference appeared to be less than 250 ms between all the devices on each network, meaning overall latency from publish glass to playback glass fell between 400–650 ms when using the OBS WebRTC ingest."
Suffice it to say that WebRTC is finally out of kindergarten and moving into the elementary grades. Which grade exactly? Well, that likely depends on which web browser you're using and which server technology or platform your WebRTC implementation uses.
VideoRx CTO Robert Reinhardt discusses how using various server-side architectures with WebRTC is like to play out, whether it's open course, commercial/licensed server, or cloud services, in this clip from Streaming Media West Connect.
VideoRx CTO Robert Reinhardt discusses client-side architecture issues and pain points unique to WebRTC in this clip from Streaming Media West Connect.
VideoRx CTO Robert Reinhardt discusses WebRTC's emergence as a low-latency option for one-to-many streaming, and the challenges of scaling it in this clip from his presentation at Streaming Media West Connect.