.. 标题：TCP 最佳窗口大小计算器
.. slug：tcp 最佳窗口大小计算器
.. 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：使用给定 RTT 和带宽的带宽延迟乘积计算最佳 TCP 窗口大小。最大化长网络路径上的吞吐量。
..类型：文本
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<div class="calc-container">
<div class="calc-header">
<h2>TCP 最佳窗口大小计算器</h2>
<p>根据您的链接速度和网络延迟计算最大化吞吐量所需的最佳 TCP 窗口大小。</p>
<div class="input-grid">
<div class="input-group">
<label for="linkspeed">链接速度（Gbps）：</label>
<input id="linkspeed" placeholder="e.g., 1 or 10" type="text" value="1"/>
</div>
<div class="input-group">
<label for="rtt">往返时间（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()">计算</button>
</div>
<div class="help-text">
<strong>提示：</strong>常用RTT值：本地网络（0.001s）、区域（0.01s）、跨国（0.05s）、国际（0.1s）</div>
</div>
<div class="result-section" id="resultsSection">
<div class="section-header" onclick="toggleSection('results')">
<h3><span class="icon">📊</span>计算结果</h3>
<span class="section-toggle">▼</span>
</div>
<div class="section-content" id="resultsContent">
<div class="data-row">
<div class="data-label">TCP 窗口大小：</div>
<div class="data-value highlight" id="tcpwindowBytes">-</div>
</div>
<div class="data-row">
<div class="data-label">TCP 窗口大小：</div>
<div class="data-value highlight" id="tcpwindowKBytes">-</div>
</div>
<div class="formula-box">
<strong>公式：</strong>带宽 (bps) × RTT（秒） ÷ 8 = TCP 窗口（字节）</div>
</div>
</div>
<div class="info-section">
<h3>系统配置变更</h3>
<div class="info-content">
<p>每个操作系统都需要不同的配置更改来调整 TCP 接收窗口。</p>
<h4>视窗XP</h4>
<ul>
<li>打开<code>regedit.exe</code></li>
<li>浏览至<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>请注意，可以在同一页面上调整传输性能的其他几个因素。请访问 Microsoft 了解更多详细信息。</p>
<h4>Windows 7、8 和 10</h4>
<ul>
<li>打开<code>regedit.exe</code></li>
<li>浏览至<code>HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters</code></li>
<li>您可以更改<code>GlobalMaxTcpWindowSize</code></li>
</ul>
<p>请注意，可以在同一页面上调整传输性能的其他几个因素。请访问 Microsoft 了解更多详细信息。</p>
<h4>Linux</h4>
<p>由于 Linux 有多种变体，因此下面并未描述所有配置选项。不过，以下命令可能会对您有所帮助。首先查看当前配置的网络设置使用：</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>编辑配置：</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>配置最大操作系统接收缓冲区大小</li>
</ul>
</li>
<li><code>sysctl -w net.core.wmem_max=8388608</code>
<ul>
<li>配置最大操作系统发送缓冲区大小</li>
</ul>
</li>
<li><code>sysctl -w net.core.rmem_default=65536</code>
<ul>
<li>配置默认操作系统接收缓冲区大小</li>
</ul>
</li>
<li><code>sysctl -w net.core.wmem_default=65536</code>
<ul>
<li>配置默认操作系统发送缓冲区大小</li>
</ul>
</li>
</ul>
<p>请注意，这些值不一定是您要使用的最终设置。如果您有 Redhat 企业支持或 Ubuntu 企业支持，他们可以提供进一步帮助。</p>
<p><strong>笔记：</strong>65,535 字节是历史上的最大值。然而，IETF RFC 1323 适应更大的尺寸。</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
    document.getElementById("resultsSection").classList.add("show");

    // 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>