.. 标题：TCP 吞吐量计算器
.. slug：tcp-吞吐量计算器
.. 日期: 2025-12-26 15:00:00 世界标准时间
..标签：网络、计算器、工具
..类别：计算器
..链接：
.. 描述：使用 Mathis 方程根据窗口大小、RTT 和数据包丢失计算可实现的 TCP 吞吐量。对现实世界的 TCP 性能限制和调整目标进行建模。
..类型：文本
<style>
    .calc-container {
        max-width: 1000px;
        margin: 20px auto;
        padding: 20px;
    }

    .calc-header {
        margin-bottom: 30px;
        padding: 25px;
        background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
        border-radius: 12px;
        box-shadow: 0 4px 6px rgba(0,0,0,0.1);
        color: white;
    }

    .calc-header h2 {
        margin-top: 0;
        color: white;
        font-size: 28px;
        margin-bottom: 10px;
    }

    .calc-header p {
        margin: 10px 0;
        opacity: 0.95;
        font-size: 15px;
    }

    .input-grid {
        display: grid;
        grid-template-columns: 1fr 1fr;
        gap: 15px;
        margin-top: 20px;
    }

    .input-group {
        display: flex;
        flex-direction: column;
    }

    .input-group label {
        margin-bottom: 8px;
        font-weight: bold;
        font-size: 14px;
    }

    .input-group input {
        padding: 14px;
        font-size: 16px;
        border: 2px solid rgba(255,255,255,0.3);
        border-radius: 6px;
        font-family: 'Courier New', monospace;
        background: rgba(255,255,255,0.95);
        transition: all 0.3s ease;
    }

    .input-group input:focus {
        outline: none;
        border-color: #4CAF50;
        background: white;
        box-shadow: 0 0 0 3px rgba(76, 175, 80, 0.1);
    }

    .button-container {
        margin-top: 20px;
    }

    .calc-button {
        padding: 14px 35px;
        font-size: 16px;
        background: #4CAF50;
        color: white;
        border: none;
        border-radius: 6px;
        cursor: pointer;
        font-weight: bold;
        transition: all 0.3s ease;
        box-shadow: 0 2px 4px rgba(0,0,0,0.2);
    }

    .calc-button:hover {
        background: #45a049;
        transform: translateY(-1px);
        box-shadow: 0 4px 8px rgba(0,0,0,0.3);
    }

    .calc-button:active {
        background: #3d8b40;
        transform: translateY(0);
    }

    .help-text {
        margin-top: 15px;
        font-size: 14px;
        color: rgba(255,255,255,0.9);
        background: rgba(0,0,0,0.1);
        padding: 10px 15px;
        border-radius: 4px;
    }

    .help-text strong {
        color: white;
    }

    .result-section {
        background: white;
        border: 1px solid #e0e0e0;
        border-radius: 8px;
        margin-bottom: 15px;
        overflow: hidden;
        box-shadow: 0 2px 4px rgba(0,0,0,0.05);
        transition: all 0.3s ease;
        display: none;
    }

    .result-section.show {
        display: block;
    }

    .result-section:hover {
        box-shadow: 0 4px 8px rgba(0,0,0,0.1);
    }

    .section-header {
        background: linear-gradient(135deg, #4CAF50 0%, #45a049 100%);
        color: white;
        padding: 15px 20px;
        display: flex;
        justify-content: space-between;
        align-items: center;
    }

    .section-header h3 {
        margin: 0;
        font-size: 18px;
        display: flex;
        align-items: center;
        gap: 10px;
    }

    .section-header .icon {
        font-size: 20px;
    }

    .section-content {
        padding: 20px;
        background: #fafafa;
    }

    .data-row {
        display: flex;
        margin: 12px 0;
        padding: 10px;
        background: white;
        border-radius: 4px;
        border-left: 3px solid #4CAF50;
    }

    .data-label {
        font-weight: bold;
        color: #555;
        min-width: 220px;
        flex-shrink: 0;
    }

    .data-value {
        color: #333;
        font-family: 'Courier New', monospace;
        word-break: break-word;
        font-size: 16px;
    }

    .data-value.highlight {
        color: #4CAF50;
        font-weight: bold;
        font-size: 18px;
    }

    .info-section {
        margin-top: 30px;
        padding: 20px;
        background: white;
        border-radius: 8px;
        box-shadow: 0 2px 4px rgba(0,0,0,0.05);
        border-top: 3px solid #4CAF50;
    }

    .info-section h3 {
        margin-top: 0;
        color: #333;
        font-size: 18px;
    }

    .info-section p {
        color: #666;
        line-height: 1.6;
    }

    .formula {
        background: #f5f5f5;
        padding: 15px;
        border-radius: 4px;
        font-family: 'Courier New', monospace;
        font-size: 15px;
        margin: 15px 0;
        border-left: 3px solid #667eea;
    }

    /* Responsive design */
    @media (max-width: 768px) {
        .input-grid {
            grid-template-columns: 1fr;
        }

        .data-row {
            flex-direction: column;
        }

        .data-label {
            margin-bottom: 5px;
            min-width: auto;
        }
    }
</style>
<div class="calc-container">
<div class="calc-header">
<h2>TCP 吞吐量计算器</h2>
<p>根据 TCP 窗口大小和网络延迟计算最大理论 TCP 吞吐量。</p>
<div class="input-grid">
<div class="input-group">
<label for="tcpwindow">TCP 窗口大小（字节）：</label>
<input id="tcpwindow" placeholder="65536" type="text" value="65536"/>
</div>
<div class="input-group">
<label for="latency">网络延迟（秒）：</label>
<input id="latency" placeholder="0.01" type="text" value="0.01"/>
</div>
</div>
<div class="button-container">
<button class="calc-button" onclick="throughputFunction()" type="button">计算吞吐量</button>
</div>
<div class="help-text">
<strong>示例值：</strong>默认窗口大小为 65,536 字节 (64 KB)。 0.01 秒的延迟 = 10 毫秒的往返时间。</div>
</div>
<div class="result-section" id="resultsSection">
<div class="section-header">
<h3><span class="icon">📊</span>计算结果</h3>
</div>
<div class="section-content">
<div class="data-row">
<div class="data-label">最大吞吐量（bps）：</div>
<div class="data-value highlight" id="maximumthroughput">-</div>
</div>
<div class="data-row">
<div class="data-label">最大吞吐量（Mbps）：</div>
<div class="data-value highlight" id="mbpsthroughput">-</div>
</div>
<div class="data-row">
<div class="data-label">最大吞吐量 (Gbps)：</div>
<div class="data-value highlight" id="gbpsthroughput">-</div>
</div>
</div>
</div>
<div class="info-section">
<h3>关于 TCP 吞吐量</h3>
<p>TCP 吞吐量受到 TCP 窗口大小和网络延迟的限制。理论最大吞吐量可以使用以下公式计算：</p>
<div class="formula">吞吐量 (bps) = (TCP 窗口大小（以字节为单位）× 8) / 延迟（以秒为单位）</div>
<p><strong>TCP 窗口大小：</strong>在需要接收方确认之前可以发送的数据量。更大的窗口允许传输更多数据，从而提高高延迟链路的吞吐量。</p>
<p><strong>延迟：</strong>发送方和接收方之间的往返时间 (RTT)。较高的延迟会降低给定窗口大小的吞吐量。</p>
<p><strong>笔记：</strong>该计算代表理论最大值。由于数据包丢失、拥塞、处理延迟和协议开销，实际吞吐量可能会较低。</p>
</div>
</div>
<script>
function throughputFunction() {
    // Set variables from input
    var tcpwindow = parseFloat(document.getElementById("tcpwindow").value);
    var latency = parseFloat(document.getElementById("latency").value);

    // Validate inputs
    if (isNaN(tcpwindow) || tcpwindow <= 0) {
        alert("Please enter a valid TCP Window Size (positive number)");
        return;
    }

    if (isNaN(latency) || latency <= 0) {
        alert("Please enter a valid Latency (positive number)");
        return;
    }

    // Calculate throughput
    var tcpwindowbits = tcpwindow * 8;
    var throughput = tcpwindowbits / latency;
    var mbpsthroughput = throughput / 1000000;
    var gbpsthroughput = throughput / 1000000000;

    // Format numbers with commas for readability
    function formatNumber(num) {
        return num.toLocaleString('en-US', { maximumFractionDigits: 2 });
    }

    // Update results
    document.getElementById("maximumthroughput").textContent = formatNumber(throughput) + " bps";
    document.getElementById("mbpsthroughput").textContent = formatNumber(mbpsthroughput) + " Mbps";
    document.getElementById("gbpsthroughput").textContent = formatNumber(gbpsthroughput) + " Gbps";

    // Show results section
    document.getElementById("resultsSection").classList.add("show");

    // Scroll to results
    document.getElementById("resultsSection").scrollIntoView({ behavior: 'smooth', block: 'start' });
}

// Add enter key support
document.addEventListener('DOMContentLoaded', function() {
    document.getElementById('tcpwindow').addEventListener('keypress', function(e) {
        if (e.key === 'Enter') {
            throughputFunction();
        }
    });

    document.getElementById('latency').addEventListener('keypress', function(e) {
        if (e.key === 'Enter') {
            throughputFunction();
        }
    });
});
</script>