UDP vs. TCP: Key Differences and TCP Retransmission Explained

(1) UDP and TCP are two fundamental protocols in computer networking. UDP (User Datagram Protocol) is a connectionless protocol, meaning it doesn't require establishing a connection before sending data. Each datagram is independent, and there's no handshake or guarantee of order or delivery. On the other hand, TCP (Transmission Control Protocol) is connection-oriented. It necessitates a connection setup through a handshake before data transmission, ensuring ordered delivery and employing acknowledgment and retransmission mechanisms for reliable data transfer.

(2) The TCP timeout retransmission mechanism is a cornerstone of TCP's reliability. When a sender transmits a segment, it starts a timer. If the receiver doesn't acknowledge receipt within a specific time, the sender retransmits the segment. This principle ensures that data is delivered even if packets are lost in transit. Several algorithms govern TCP retransmission strategies, including:

1. Slow Start Algorithm: Gradually increases the sending rate to avoid overwhelming the network.
2. Congestion Avoidance Algorithm: Maintains a stable sending rate while avoiding network congestion.
3. Fast Retransmit Algorithm: Quickly retransmits lost segments upon receiving duplicate acknowledgments.
4. Fast Recovery Algorithm: Recovers from congestion faster by adjusting the sending rate based on the number of duplicate acknowledgments.

(3) 4399, a prominent exporter of overseas games, can enhance their global network performance by implementing these strategies:

1. Optimizing server network bandwidth: Increasing server capacity for efficient data processing.
2. Utilizing caching techniques: Reducing server requests through data storage closer to users.
3. Establishing servers in diverse locations: Minimizing data transmission distances and latency.
4. Implementing load balancing: Distributing traffic across multiple servers to reduce peak loads.
5. Employing CDN (Content Delivery Network) technology: Accelerating network access speeds by distributing content closer to users.