Throughput

Definition

• Throughput_처리량
• The actual rate at which data is successfully transmitted over a network from one point to another in a given time period. It is usually measured in bits per second (bps), bytes per second (Bps), or data packets per second (pps).

 

 

Key Characteristics

1. Actual Performance: Throughput measures the real-world performance of a network, taking into account all inefficiencies and overheads.
2. Effective Data Rate: Reflects the amount of useful data received, excluding protocol overhead and retransmissions.

 

Factors Affecting Throughput

1. Bandwidth:
   •   Maximum capacity of the network link.
   •   Throughput is often less than the available bandwidth due to various factors like overhead and network conditions.
2. Latency_지연시간:
   •   Delay between sending and receiving data.
   •   High latency can reduce throughput, especially in protocols that require acknowledgment (like TCP) 
3. Packet Loss:
   •   Loss of packets during transmission.
   •   Requires retransmissions, reducing effective throughput.
4. Network Congestion:
   •   High traffic can lead to congestion, increasing packet loss and delays.
   •   Congestion control mechanisms in protocols like TCP can throttle throughput.
5. Protocol Overhead:
   •   Additional bits required for headers, footers, and control information.
   •   Higher overhead means less data payload and lower throughput.
6. Error Rates:
   •   Bit errors can cause retransmissions, affecting throughput.
   •   Error correction mechanisms add overhead, reducing throughput.
7. Hardware Limitations:
   •   Performance of routers, switches, and network interface cards (NICs).
   •   Processing power and buffering capabilities impact throughput.
8. Distance and Medium:
   •   Longer distances and certain transmission media (like wireless) can introduce more errors and delays.

 

Latency

 

Practical Considerations

• Application Needs: Different applications (e.g., video streaming vs. web browsing) have different throughput requirements.
• User Experience: Throughput impacts user experience directly, especially in real-time applications like VoIP and online gaming.
• Cost vs. Performance: Balancing the cost of network infrastructure against the desired throughput.

Understanding throughput and its influencing factors is crucial for designing, managing, and optimising network performance to meet the needs of users and applications.