Bridge - execution time

Hello, I have tried the Bridge.ino example with the following batch, to see how quickly the LED13 commute; and to see a witch speed GET command can be executed:

:start
c:\curl\curl http://Yunmasur.local/arduino/digital/13/1
c:\curl\curl http://Yunmasur.local/arduino/digital/13/0
goto start

In order to be independent of a browser, the (excellent) program CURL is used for launch the GET query. The measured time of one phase is 2,8 sec. That give a frequency of 0.17 Hz. The sketch run at ~20 Hz. The linino, OpenWRTYun Attitude Adjustment 1 / LuCI 0.11 Branch (0.11+svn10180) no idea; but it is certainly the weak point.

Does anybody and idea, why the response is so slow?