## 3 System Design  
### System Design Overview  
The decentralized multi-venue real-time video broadcasting system proposed in this paper adopts an innovative peer-to-peer architectural design. The core objective of the proposed system is to minimize system complexity and deployment costs while simultaneously ensuring low latency and high reliability. Fundamentally, the system is composed of three core components: the _Streaming Source_, the _Playback & Relay Node_, and a _Distributed IP Table Management_ module. The overall architecture is shown in Figure 2. To summarize the integration with the overall system architecture, our system's implementation involves the streaming source establishing an srt:// listener via FFmpeg to receive video streams initiated by OBS or production software. The first node in the chain then operates in caller mode, actively connecting to the first downstream node. All subsequent relay nodes function in a listener-caller combination mode, sequentially relaying the stream. All nodes manage control signaling through WebSocket connections, handling node registration, link updates, and broken link repairs. When the chain topology changes, SRT connections are automatically negotiated, establishing a fully decentralized, stable, chain-based media relay system. The system architecture adheres to a set of fundamental design principles that guide its construction and operation. Firstly, the _Principle of Simplicity_ is achieved by employing a chain topology to reduce routing complexity, thereby avoiding the need for complex network discovery and maintenance mechanisms. Secondly, the _Principle of Reliability_ is upheld through the integration of multi-layered fault detection and self-healing mechanisms, ensuring that single points of failure do not compromise overall service continuity. Thirdly, the _Principle of Scalability_ is supported by enabling dynamic node joining and departure without requiring a complete network reconfiguration. Finally, the _Principle of Security_ is paramount, with end-to-end encryption implemented across the entire link to guarantee the confidentiality and integrity of data transmission. A crucial enabler for this system is its reliance on the _IPv6 Network Foundation_. The system fully leverages the technical advantages of the IPv6 protocol, where each participating  
Figure 2: Overall system architecture design. node acquires a globally unique IPv6 address via DHCPv6 or SLAAC mechanisms [23]. Compared with the intricate NAT traversal mechanisms prevalent in IPv4 environments, IPv6's native end-to-end connectivity significantly simplifies the P2P connection establishment process. Complementing this, the node discovery mechanism is based on a pre-configured list of seed nodes, allowing new nodes to register their IPv6 address and port information with a coordination server via HTTPS RESTful API. This robust network foundation allows for the implementation of the _Chain Transmission Topology_. The system adopts a unidirectional chain structure, where the video stream originates from the streaming source, sequentially traverses intermediate relay nodes, and ultimately reaches the tail node of the chain. To formalize this, let the set of nodes be represented as \(N=\{n_{0},n_{1},\ldots,n_{k}\}\), where \(n_{0}\) is the streaming source and \(n_{k}\) is the chain tail node. The transmission path can thus be expressed as  
\[Path=n_{0}\xrightarrow{\mathit{SRT}}n_{1}\xrightarrow{\mathit{SRT}}n_{2} \xrightarrow{\mathit{SRT}}\cdots\xrightarrow{\mathit{SRT}}n_{k} \tag{1}\]  
Each relay node \(n_{i}\) (\(i\in[1,k-1]\)) concurrently performs both reception and forwarding functions.