Testing Wowza's Real-Time Streaming at Scale

With all the hype surrounding low latency, 流媒体特约编辑蒂姆·西格林来看看这些说法 Wowza is making around its new real-time streaming at scale offering.

Siglin, 一位资深顾问和评论家，拥有超过三十年的交互式视频测试经验, streaming, and videoconferencing hardware and software, 现在，作为这家非营利机构的创始执行董事，他的职责之一是提供测试验证 Help Me Stream Research Foundation. Wowza与Help Me Stream进行了接触，希望对其新增的Wowza流媒体云进行评估, known as Real-Time Streaming at Scale, a few weeks before general availability (GA). [披露:流媒体编辑兼副总裁埃里克·舒马赫-拉斯穆森是“帮助我流媒体研究基金会”的志愿者主席.]

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, 测试是在“帮助我流”位于金斯波特的测试设施进行的, 田纳西州和该公司没有影响测试环境.

Wowza的观点是，有许多用户希望实现实时传输，而不是典型的基于缩放的12个甚至100个观众.

"In a recent Wowza survey, 57%的受访者表示，他们希望直播工作流程的延迟低于一秒," Wowza's Jon Duncan wrote in the official GA announcement from Wowza, 注意到调查结果表明需要一个可扩展到300多名观众的解决方案. 尽管如此，大多数人仍然会遇到3-45秒范围内的延迟."

“我们设计了大规模实时流媒体功能来满足这些需求, 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. 有些人对跨多个观众的实时流的完全同步感兴趣, even if it means a short delay, 而其他人则更关心尽可能低的延迟.

With a background in videoconferencing, before entering the streaming space 24 years ago, Siglin测试超低延迟(玻璃对玻璃的延迟小于250毫秒)的经验在测试Wowza的解决方案时非常有用.

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, 需要平衡RTMP流-流媒体行业的支柱, even though it's decades old—with newer, more interactive low-latency protocols.

Siglin notes that RTMP has found new uses, 包括开源视频混合和流媒体工具，如OBS, Wowza也为它的大规模实时流媒体客户提供了这个版本.

“在RTMP的初始服务器被弃用之后，我们不仅会使用更长时间(想想Flash Media server)。, but the streaming industry is finding new uses for RTMP," said Siglin in his review. “其中之一是RTMP生成低延迟编码的能力，现在可以通过像Wowza这样的解决方案进行扩展，而最初的RTMP流服务器无法执行."

Wowza提供的OBS版本既可以生成WebRTC流，也可以生成RTMP流, Siglin在他的评论中指出，WebRTC在Help Me Stream Research测试台上确实提供了更低的总体延迟.

“我们的蜂窝数据回放测试显示，通过连接到电缆调制解调器的WiFi接入点进行回放的延迟略低," said Siglin. “但每个网络上所有设备之间的差异似乎不到250毫秒, 这意味着当使用OBS WebRTC摄取时，从发布玻璃到播放玻璃的总延迟时间在400-650毫秒之间."