On October 20, 2025, AWS experienced a severe failure in its US-East-1 region. According to AWS’s public updates, the incident stemmed from a race condition in the DNS management system, which caused large-scale DNS record clearing and IP resolution failure. This fault cascaded across multiple core services—first DynamoDB, then EC2, and finally Network Load Balancer—highlighting the risks of relying on a single-cloud architecture rather than a robust multi-cloud architecture. The outage rendered large portions of AWS infrastructure unavailable.
The impact was monumental, affecting thousands of businesses across social media, finance, gaming, and streaming. This event, AWS’s most significant downtime in four years, potentially caused tens of billions in losses and served as a stark reminder of the systemic risk inherent in depending on a single cloud region.
In RTC systems—video calls, streaming, or gaming—any failure directly harms user experience, reliability, and trust. It’s a powerful reminder: relying on a single cloud region is a systemic risk, not a mere bug.
That risk motivated us at ZEGOCLOUD to build differently. Our multi-cloud RTC platform is designed to excel even when the unexpected occurs.
Why Multi-Cloud Architecture Matters for Real-Time Communication
Real-time workloads differ fundamentally from typical SaaS applications:
- Latency-sensitive — sub-200 ms round-trip time is often required for fluid interaction.
- Connection-intensive — apps may need to support millions of concurrent sessions simultaneously.
- Highly dynamic — traffic surges, geographic shifts, and unpredictable user behavior are the norm.
In such an environment, even transient issues — packet loss, DNS hiccups, local network hiccups — can cause visible disruptions: call drops, lag, broken streams, degraded quality.
This is why ZEGOCLOUD built MSDN 2.0, an architecture designed from the ground up for extreme reliability, rapid failover, and intelligent routing—across multiple cloud providers and more than 200 global data centers.
ZEGOCLOUD MSDN 2.0: A Multi-Cloud Architecture Built for Failure
Beyond “multi-AZ”: true multi-cloud resilience
MSDN 2.0 — ZEGOCLOUD’s self-developed Media Streaming Distribution Network — isn’t just a multi-region or multi-AZ setup. It’s a true multi-cloud architecture that draws on infrastructure from multiple global cloud providers, unified into a resilient and adaptive network.
At its core, MSDN 2.0 features a decentralized, layered network that pre-plans multiple communication paths between any source and destination. It continuously monitors route performance, dynamically selects the optimal path, and instantly switches when degradation or failure occurs.
These design principles translate into three key capabilities:
- Edge Reuse and Resource Sharing
By decoupling central and edge resources, we unlock a fluid, shared pool of edge capacity that can be dynamically allocated across the entire network. It supports the horizontal expansion and free combination of edge nodes, improving resource utilization and architectural flexibility.
- Elastic Scaling and Horizontal Expansion
An intelligent load-balancing mechanism enables second-level expansion to handle sudden traffic surges of tens of millions of users. The system performs real-time resource scheduling and re-allocation, guaranteeing stability and performance during peak loads.
- Flexible Edge Layering
Edge nodes are managed in a multi-layer structure, akin to a logistics network with regional hubs and local delivery stations. This allows us to optimally deploy services close to users, regardless of their location or local cloud provider, ensuring the fastest possible response.
In simple terms, MSDN 2.0 is like an “intelligent and flexible service network”. It integrates scattered resources into a large resource pool, which can be flexibly combined and expanded to avoid resource waste and adapt to business growth. In the face of a large number of user accesses, the system can automatically allocate resources like an “elastic rubber band” to maintain a smooth experience. Moreover, it layers the service nodes, similar to the layering of regional outlets and community sites of express delivery, which can deliver services to users more efficiently, improve the response speed, and make the system flexible, capable of handling large traffic, and fully utilize resources.
Automated Disaster Recovery — Invisible to End Users
This sophisticated multi-cloud architecture enables automated, seamless disaster recovery on two critical fronts:
Edge Disaster Recovery: Our architecture ensures uninterrupted service by instantly and seamlessly redirecting traffic to standby nodes, guaranteeing business continuity through inherent resilience.
Central Disaster Recovery: An automatic cloning and reconstruction mechanism is adopted. When the central node fails, the edge nodes can automatically migrate to available central nodes. With built-in redundancy and seamless automatic switching, central-layer services stay fully available and reliably uninterrupted.
This is like the system having an “automatic backup plan”, which can switch seamlessly when problems occur, and users are completely unaware. There is a “backup plan” on the edge side. If a service point experiences an issue, the backup seamlessly takes over, ensuring uninterrupted operations. At the central level, any issue with the core “brain” node triggers automatic replication, instantly establishing a new “brain” while edge services reconnect smoothly—keeping the system running flawlessly. The whole process requires no manual intervention, and the business continues to operate, making the system fearless of failures.
How ZEGOCLOUD Handles Real-World Failure Scenarios
The global network is complex and changeable, and the network infrastructure in different regions varies. Often, due to various reasons such as machine downtime, data center failures, and public network link jitter between IDCs, push – pull streaming may fail or the video quality may deteriorate.
A theoretical architecture is only as good as its practical performance. The table below illustrates how our multi-cloud architecture directly addresses common points of failure that cripple single-cloud setups.
| Failure Scenario | Single-Cloud Risk | ZEGOCLOUD’s Multi-Cloud Solution |
| Single-Machine Failure | Service interruption if load balancer fails. | Automatic node removal & SDK retry logic to a healthy machine. |
| Data Center / Availability Zone Failure | Entire service region becomes unavailable. | SDK receives multiple nodes from different data centers and retries to a normal one. |
| Sudden Excessive Traffic | Cloud provider rate-limiting or throttling can cause outages. | Automatic scaling across cloud resources, rate-limiting, and isolated deployment prevent cascade failure. |
| External Service Failure (e.g., CDN) | Dependent on a single provider’s CDN network. | Self-developed intelligent scheduling selects the best CDN node from multiple options. |
| Control Center/Cluster Failure | Single point of failure for management and control. | Global multi-center control plane. If Center A fails, traffic is routed to Center B. |
| Local Network Line Failure | Latency or failure within a single cloud’s network. | Relies on global nodes from multiple cloud providers, with seamless route switching via MSDN. |
How ZEGOCLOUD Optimizes Edge-to-User Connectivity for Maximum Reliability
The “last mile” — from edge nodes to end-user networks — is often the most unpredictable. Variations in IP accuracy, protocol restrictions, operator routing, and local network configurations can all degrade service quality. To ensure stable and efficient real-time streaming globally, ZEGOCLOUD implements a comprehensive set of optimization strategies across both the SDK and server layers.
1. Ensuring Accurate IP Resolution
ZEGOCLOUD continuously corrects known invalid IPs and IP ranges, regularly scans for segment changes, and updates its IP library in real time. This prevents routing errors caused by inaccurate IP data and improves the precision of node scheduling.
2. Handling UDP Restrictions in User Networks
Many user environments restrict UDP traffic. ZEGOCLOUD’s edge nodes support dual protocols (UDP/TCP), and the SDK automatically switches to the available protocol when it detects UDP limitations, ensuring uninterrupted streaming.
3. Bypassing Port Restrictions
To cope with restrictive firewall or NAT configurations, ZEGOCLOUD provides nodes on multiple ports. When the client’s current port is blocked, the SDK retries on alternate ports or nodes to maintain stable connectivity.
4. Managing Multiple Network Exits
When a user’s network routes outbound traffic through multiple exits, the client-facing IP may differ from the scheduled IP. ZEGOCLOUD’s media nodes detect this mismatch and trigger a real-time re-scheduling process, enabling the SDK to reconnect to the most appropriate node based on the actual exit IP.
5. Addressing Operator-Specific Connectivity Issues
Performance can vary across operators and cloud providers. ZEGOCLOUD mitigates this through both client-side and server-side intelligence:
- SDK: conducts real-time node quality checks, historical-data-based scheduling, and automatic reconnection when node quality drops.
- Server: a quality operations system continuously analyzes global network performance, scores end-user network quality, and dynamically adjusts the scheduling strategy across clusters.
Through these measures, ZEGOCLOUD significantly reduces typical edge-to-user connectivity failures and maximizes the probability of smooth, low-latency RTC/streaming experiences for every user — everywhere.
Conclusion
The recent AWS outage was not an anomaly but a lesson in modern system design. Reliance on a single cloud region is a preventable risk. ZEGOCLOUD’s foundation on a resilient multi-cloud architecture provides a proven, robust framework for real-time communication, ensuring business continuity even when underlying cloud providers experience partial failures.
Building high-availability RTC is a complex challenge, and a true multi-cloud architecture is the cornerstone of its solution.
Ready to build your service on a more resilient foundation? Click here to schedule a free consultation with our solutions architect and explore the technical details of our MSDN 2.0 architecture.
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