.. 標題：TCP 最佳視窗大小計算器
.. slug：tcp 最佳視窗大小計算器
.. 日期: 2025-12-26 15:00:00 世界標準時間
..標籤：網路、計算機、工具
..類別：計算器
..連結：
.. 描述：使用給定 RTT 和頻寬的頻寬延遲乘積計算最佳 TCP 視窗大小。最大化長網路路徑上的吞吐量。
..類型：文字
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</style>
<div class="calc-container">
<div class="calc-header">
<h2>TCP 最佳視窗大小計算器</h2>
<p>根據您的連結速度和網路延遲計算最大化吞吐量所需的最佳 TCP 視窗大小。</p>
<div class="input-grid">
<div class="input-group">
<label for="linkspeed">連結速度（Gbps）：</label>
<input id="linkspeed" placeholder="e.g., 1 or 10" type="text" value="1"/>
</div>
<div class="input-group">
<label for="rtt">往返時間（秒）：</label>
<input id="rtt" placeholder="e.g., 0.01" type="text" value=".01"/>
</div>
</div>
<div class="button-group">
<button class="calc-button" onclick="tcpwindowFunction()">計算</button>
</div>
<div class="help-text">
<strong>提示：</strong>常用RTT值：本地網路（0.001s）、區域（0.01s）、跨國（0.05s）、國際（0.1s）</div>
</div>
<div class="result-section" id="resultsSection">
<div class="section-header" onclick="toggleSection('results')">
<h3><span class="icon">📊</span>計算結果</h3>
<span class="section-toggle">▼</span>
</div>
<div class="section-content" id="resultsContent">
<div class="data-row">
<div class="data-label">TCP 視窗大小：</div>
<div class="data-value highlight" id="tcpwindowBytes">-</div>
</div>
<div class="data-row">
<div class="data-label">TCP 視窗大小：</div>
<div class="data-value highlight" id="tcpwindowKBytes">-</div>
</div>
<div class="formula-box">
<strong>公式：</strong>頻寬 (bps) × RTT（秒） ÷ 8 = TCP 視窗（位元組）</div>
</div>
</div>
<div class="info-section">
<h3>系統配置變更</h3>
<div class="info-content">
<p>每個作業系統都需要不同的設定變更來調整 TCP 接收視窗。</p>
<h4>視窗XP</h4>
<ul>
<li>打開<code>regedit.exe</code></li>
<li>瀏覽至<code>HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters</code></li>
<li>您可以更改<code>TcpWindowSize</code>和<code>GlobalMaxTcpWindowSize</code></li>
</ul>
<p>請注意，可以在同一頁上調整傳輸效能的其他幾個因素。請造訪 Microsoft 以了解更多詳細資訊。</p>
<h4>Windows 7、8 和 10</h4>
<ul>
<li>打開<code>regedit.exe</code></li>
<li>瀏覽至<code>HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters</code></li>
<li>您可以更改<code>GlobalMaxTcpWindowSize</code></li>
</ul>
<p>請注意，可以在同一頁上調整傳輸效能的其他幾個因素。請造訪 Microsoft 以了解更多詳細資訊。</p>
<h4>Linux</h4>
<p>由於 Linux 有多種變體，因此下面並未描述所有設定選項。不過，以下命令可能對您有幫助。首先查看目前配置的網路設定使用情況：</p>
<ul>
<li><code>cat /proc/sys/net/ipv4/tcp_mem</code></li>
<li><code>cat /proc/sys/net/core/rmem_default</code></li>
<li><code>cat /proc/sys/net/core/rmem_max</code></li>
<li><code>cat /proc/sys/net/core/wmem_default</code></li>
<li><code>cat /proc/sys/net/core/wmem_max</code></li>
<li><code>cat /proc/sys/net/core/optmem_max</code></li>
</ul>
<p>編輯配置：</p>
<ul>
<li><code>sysctl -p /etc/sysctl.conf</code></li>
</ul>
<ul>
<li><code>sysctl -w net.core.rmem_max=8388608</code>
<ul>
<li>配置最大作業系統接收緩衝區大小</li>
</ul>
</li>
<li><code>sysctl -w net.core.wmem_max=8388608</code>
<ul>
<li>配置最大作業系統傳送緩衝區大小</li>
</ul>
</li>
<li><code>sysctl -w net.core.rmem_default=65536</code>
<ul>
<li>配置預設作業系統接收緩衝區大小</li>
</ul>
</li>
<li><code>sysctl -w net.core.wmem_default=65536</code>
<ul>
<li>配置預設作業系統傳送緩衝區大小</li>
</ul>
</li>
</ul>
<p>請注意，這些值不一定是您要使用的最終設定。如果您有 Redhat 企業支援或 Ubuntu 企業支持，他們可以提供進一步協助。</p>
<p><strong>筆記：</strong>65,535 位元組是歷史上的最大值。然而，IETF RFC 1323 適應更大的尺寸。</p>
</div>
</div>
</div>
<script>
function tcpwindowFunction() {
    // Set variables from input
    var linkspeed = document.getElementById("linkspeed").value;
    var rtt = document.getElementById("rtt").value;

    // Convert Gbps to bps
    var bps = linkspeed * 1000000000;

    var tcpwindow = bps * rtt;
    var tcpwindowBytes = tcpwindow / 8;
    var tcpwindowKBytes = tcpwindow / 8;

    // Format numbers with commas for readability
    var tcpwindowBytesResult = tcpwindowBytes.toLocaleString() + " Bytes";
    var tcpwindowKBytesResult = (tcpwindowBytes/1024).toLocaleString(undefined, {maximumFractionDigits: 2}) + " Kilobytes";

    document.getElementById("tcpwindowBytes").innerHTML = tcpwindowBytesResult;
    document.getElementById("tcpwindowKBytes").innerHTML = tcpwindowKBytesResult;

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

function toggleSection(sectionId) {
    const content = document.getElementById(sectionId + 'Content');
    const header = content.previousElementSibling;

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        header.classList.remove('collapsed');
    } else {
        content.classList.add('collapsed');
        header.classList.add('collapsed');
    }
}

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

    document.getElementById('rtt').addEventListener('keypress', function(e) {
        if (e.key === 'Enter') {
            tcpwindowFunction();
        }
    });

    // Auto-focus first input field
    document.getElementById('linkspeed').focus();
});
</script>