Fiddler 之弱網測試（2G,3G,4G）

1、模擬弱網環境

打開Fiddler，Rules->Performance->勾選 Simulate Modem Speeds，勾選之後訪問網站會發現網絡慢了很多

2、Fiddler弱網的原理

Rules—>Cutomize Rules打開CustomRules.js 文檔

在文件中搜索關鍵字，m_SimulateModem

1.

   // Cause Fiddler to delay HTTP traffic to simulate typical 56k modem conditions
    public static RulesOption("Simulate &Modem Speeds", "Per&formance")
    var m_SimulateModem: boolean = false;

2.

if (m_SimulateModem) {
            // Delay sends by 300ms per KB uploaded.
            oSession["request-trickle-delay"] = "300";
            // Delay receives by 150ms per KB downloaded.
            oSession["response-trickle-delay"] = "150";
        }

讓我們來分析一下這幾行代碼：

• 首先來判斷m_SimulateModem是否爲true，也就是是否設置了弱網模式。

• 如果爲弱網模式。則分析代碼

• oSession[“request-trickle-delay”] = “300”; 註釋的也很明白，Delay sends by 300ms per KB uploaded.上傳1KB需要300ms，

  轉化一下上傳速度：1Kb/0.3s = 10/3(KB/s)，也就是 3.33kb/s ，到達2G網絡標準。

• 如果你想設置上傳的速度爲50KB/s，你則需要設置Delay 時間爲 20ms

• 同樣的方法，也可以限制上傳的速度，調整oSession[“response-trickle-delay”]即可。

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網絡	上行	下載
2G	2.7K	9.6K
3G	1.8M	7.2M
4G	50M	100M

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所以得出：2G網絡配置

if (m_SimulateModem) {
            // Delay sends by 300ms per KB uploaded.
            oSession["request-trickle-delay"] = "300";
            // Delay receives by 150ms per KB downloaded.
            oSession["response-trickle-delay"] = "150";
        }

3G 網絡配置,3G 應該是2G網絡估值的1000倍速率，也就是上行和下載除去1000。

if (m_SimulateModem) {
            // Delay sends by 300ms per KB uploaded.
            oSession["request-trickle-delay"] = "0.3";
            // Delay receives by 150ms per KB downloaded.
            oSession["response-trickle-delay"] = "0.15";
        }

4G網絡配置，上行爲3G的25倍，下載爲15倍，放開延遲即可。