Tencent Cloud International Audio and Video Solution: Low Latency Live Broadcast and Global CDN Distribution Measured
Today, when sailing to Shanghai, audio and video capabilities have become the core standard of products, whether it is cross-border e-commerce live broadcast, overseas pan-entertainment and social networking, or online education. However, the physical environment facing the sea is extremely complex: cross-border network jitter, poor infrastructure in overseas small language regions, compliance requirements in different countries, etc. Minutes can make a product that runs smoothly at home "stuck into PPT" overseas ".
In order to verify the true performance of Tencent Cloud International (Tencent Cloud International) in mainstream overseas markets (especially Southeast Asia, the Middle East, and Europe and the United States), we have recently
Low-latency Live Video Broadcasting (LEB) and global CDN distribution network
A depth measurement was carried out.
Without the beautiful data of the official public relations draft, we only look at the technical performance in the real scene.
1. architecture and core technical indicators dismantling
Before entering the actual measurement, let's disassemble the "technical formula" of tengxunyun international audio and video base ". Typically, traditional overseas live broadcasts use HLS or RTMP protocols, with delays at every turn.
3 to 5 seconds
and even higher. This delay is fatal in scenarios such as e-commerce grabbing orders and even wheat interaction.
The core trump card played by Tencent Cloud International is based on
WebRTC
technology of Live Express (LEB), combined with its Global Media Delivery Network (MDN).
1. Core technology architecture
Streaming end: supports standard RTMP / SRT protocol streaming, and provides WebRTC streaming SDK to reduce the first kilometer delay on the streaming side.
Transport layer: Based on Tencent's self-developed global streaming media scheduling system, it cooperates with 2800 CDN nodes around the world and uses intelligent routing algorithm to bypass public network congestion points.
Streaming end: The WebRTC stream is distributed through Live Broadcast (LEB) to realize millisecond-level decoding and rendering on the player end.
2. Indicators we focus on testing
End-to-End Delay (Latency): The absolute time difference between the time the host collects the picture and the time the viewer sees the picture.
First Frame Time: The time it takes for viewers to click to enter the live broadcast room until the screen is displayed.
Anti-packet Loss (Anti-packet Loss): Fluency performance in the event of weak network deterioration (simulating overseas 3G/4G jitter).
2. Measurement Environment and Tool Construction
In order to simulate the most realistic overseas transnational scenarios, we set up the following test environment:
Push point: Hong Kong, China (simulated offshore enterprise operations headquarters/core anchor side).
Laliu test points: Jakarta, Indonesia, Bangkok, Thailand, Riyadh, Saudi Arabia, Los Angeles, USA (double verification through overseas real cloud hosts and local real machine agents).
Comparison of Test Protocols: Tencent Cloud Fast Live (WebRTC) VS Standard Direct
Broadcast (RTMP push stream + HLS/HTTP-FLV pull stream).
Test tools: OBS Studio (push streaming), Tencent Cloud standard player SDK, and network packet loss simulation tool (Clumsy/TC).
3. Measured Data Hard Core Exposure
1. End-to-end delay test: the "life and death speed" of cross-border transmission"
We have placed a high-precision millisecond timer at the push-streaming end in Hong Kong. Test machines overseas use a fast live (LEB) player to pull the stream, and use a high frame rate camera to shoot the push-streaming screen and the pull-streaming screen at the same time to calculate the time difference between the two.
Test location
Standard Live Delay (HLS)
Standard Live Delay (HTTP-FLV)
Tencent Cloud Express Live (LEB) Delayed
Jakarta, Indonesia
6.2 seconds
2.8 seconds
420 milliseconds (0.42s)
Bangkok, Thailand
5.8 seconds
2.5 seconds
380 milliseconds (0.38s)
Saudi Riyadh
7.4 seconds
3.4 seconds
560 milliseconds (0.56s)
United States · Los Angeles
6.9 seconds
3.1 seconds
510 milliseconds (0.51s)
Measured conclusion: The traditional HLS delay cannot be used in interactive scenarios directly declared overseas. However, Tencent Cloud Express (LEB) successfully reduced the end-to-end delay around the world to less than 600 milliseconds. Due to the close physical distance in Southeast Asia, the delay is even approaching 300 milliseconds. This kind of performance has been fully able to support overseas high-frequency interactive "barrage lottery" or "live with goods second kill".
2. First frame second opening rate: the key first second to retain overseas users
The upper limit of network bandwidth for overseas users (especially in Southeast Asia and Latin America) is relatively low. If the "circle" exceeds 2 seconds, the user churn rate will soar.
Under the normal network environment in various places, we conducted 50 consecutive tests of entering and leaving the studio:
The average time taken for the first frame of the fast live broadcast (LEB) is between 210ms and 350ms.
Experience perception: click to play the moment, the picture is almost "stick face" brush out. This is because WebRTC eliminates the traditional TCP three-way handshake and the complex handshake logic of the application layer, and cooperates with the cache preheating of Tengxun Cloud CDN nodes at the overseas edge layer to realize the real "second on".
3. Weak network anti-packet loss test: simulation of overseas bad network
The mobile network infrastructure in some overseas areas is not stable, and packet loss often occurs instantly. We manually introduced in the test
Network packet loss
, observe whether the picture has frequent blocking, out-of-sync sound and picture or cut-off.
In the case of 20% random packet loss: standard live broadcast (FLV) starts to appear obvious Caton for 1-2 seconds, and sound and picture starts to appear slightly out of sync. However, the fast live broadcast (LEB) still keeps the picture smooth, the sound quality is clear, and the cut-off is not triggered.
In the case of 40% extreme downlink packet loss: fast straight
Broadcast (LEB) triggers the adaptive rate reduction mechanism. Although the resolution of the picture is slightly stepped down, it can still ensure that the sound is continuous and the picture is not stuck.
This is due to Tencent Cloud's optimization at the WebRTC protocol layer.
FEC (Forward Error Correction)
algorithm and
ARQ (Automatic Repeat Request)
Mechanism. It does not blindly retransmit, but dynamically calculates the most economical packet replenishment strategy based on network conditions.
4. Global CDN Distribution Network: The "Stable" Word Tactics under Large Concurrency
Low latency is the experience of the foreground, while the concurrency and distribution capabilities of the background determine whether the system will "collapse" when the business is large ".
Tengxunyun International CDN has global 2800 + nodes, overseas nodes 1100 +, and a full-network bandwidth water reserve of more than 200T +. In our high-concurrency stress test simulation, we found that its global CDN distribution has several very obvious characteristics:
1. Intelligent routing and dynamic scheduling
Many overseas enterprises are most afraid of "late peak". From 8 pm to 11 pm, the network of overseas local operators is congested, and ordinary CDN is easy to collapse.
In the actual measurement, when a sudden congestion occurs in the local backbone network of a country, Tencent Cloud's
Global Traffic Scheduling System (GSLB)
And act smart enough. It can identify link exceptions in seconds and dynamically switch traffic to backup edge nodes or cross-border dedicated channels. For front-end users, only a very small bit rate fine-tuning is sensed, and the live broadcast is completely uninterrupted.
2. Perfect "multi-live" and compliance adaptation
Seagoing involves complex compliance issues (e. g. GDPR in Europe, CCPA in the US). Tengxun Cloud International Edition has done a thorough job in compliance. Its overseas CDN nodes have been isolated in compliance at the physical layer and data flow layer.
At the same time, its console provides extremely fine-grained configuration. For example, you can configure it with one click.
Geographic Area Access Control (Geo-blocking)
To prevent some copyrighted video streams from falling into unauthorized countries; Or for overseas anti-brush, one-click turn on advanced security protection (WAF/DDoS integrated prevention).
Guide to 5. Pit Avoidance: A Little Practical Advice for Everyone to Sail to Sea
In the actual process of docking Tengxunyun International's audio and video program, we stepped on some small pits and explored some "hidden games" that can maximize performance to share with you:
Don't be silly to only play with standard WebRTC. Although WebRTC has low latency, the native support for WebRTC in some older models or niche browsers overseas is not perfect. It is suggested to adopt the adaptive degradation strategy of Tengxun Cloud SDK when accessing: give priority to fast live broadcast (LEB). If it is detected that the equipment does not support or extremely weak network, it will be seamlessly degraded to ordinary HLS/FLV in seconds. Users will not notice, but can guarantee 100 percent availability.
Reasonable allocation of adaptive code rate (ABR) The gap between the rich and the poor in network bandwidth in overseas countries is huge. It is recommended that in the Tencent cloud audio and video transcoding template, be sure to configure
Adaptive code rate (Top Speed Codec/Extreme HD). It can reduce the bandwidth code rate by about 30% without sacrificing the image quality, which can not only help enterprises save huge overseas CDN traffic fees, but also greatly improve the playback fluency of users in low bandwidth areas.
Pay attention to the choice of overseas streaming nodes. If your anchor is in China, you must go to the overseas nodes through Tengxun Cloud's cross-border dedicated acceleration channel (SRT protocol streaming). Do not use ordinary RTMP to push hard to the overseas nodes, otherwise the first kilometer packet loss will directly destroy all the low-latency optimizations behind.
6. summary and selection suggestions
After this round of comprehensive measurement, we can give an objective portrait of Tengxun Cloud International's audio, video and CDN solutions:
Advantages: The ultra-low delay of fast live broadcast (LEB) is well-known, the cross-border distribution is on the order of 0.5 seconds, and the weak network has extremely strong anti-packet loss capability. For areas with complex network infrastructure, such as Southeast Asia and the Middle East, its dynamic scheduling capability shows extremely high stability.
Applicable scenarios: It is strongly recommended that cross-border e-commerce live broadcast, overseas pan-entertainment interaction (such as 1v1 Lianmai, language chat room), online real-time teaching, sports events overseas live broadcast and other real-time interaction requirements are extremely high, high concurrent traffic obvious business.
If your sea-going business is in a bottleneck period of "users dislike cards, interaction is too slow, and the cost of sea-going bandwidth is high", tengxunyun international version of the "fast live broadcast + global CDN" combination is indeed a hard-core choice that can be used and can directly see the improvement of business indicators.
