Capture Level的设置说明：
1、Socket level data.
Capture data using trapping on the socket level only. Port mappings apply in this case (default).
2、WinINet level data.
Capture data using hooks on the WinINet.dll API used by certain HTTP applications. The most common application that uses these hooks is Internet Explorer. Port mappings are not relevant for this level.
3、Socket level and WinINet level data.
Captures data using both mechanisms. WinINet level sends information for applications that use WinINet.dll. Socket level sends data only if it determines that it did not originate from WinINet.dll. Port mapping applies to data that did not originate from WinINet.dll.
在录制设置中：
当capture level为socket level data的时候
VuGen将捕获HTTP、SMTP、POP3、IMAP、OracleNCA和WinSocket协议
当capture level为wininet level data的时候
VuGen将捕获HTTP、FTP、Gopher协议
WinInet（“Windows Internet”）API帮助程序员使用三个常见的Internet协议，这三个协议是用于World Wide Web万维网的超文本传输协议（HTTP：Hypertext Transfer Protocol）、文件传输协议（FTP：File Transfer Protocol）和另一个称为Gopher的文件传输协议。WinInet函数的语法与常用的Win32 API函数的语法类似，这使得使用这些协议就像使用本地硬盘上的文件一样容易。
参考：
http://www.loadrunnertnt.com/concepts/difference-between-wininet-and-socket-level/
http://www.loadrunnertnt.com/how-tos/quick-and-dirty-recording-techniques-for-web-httphtml/