Esp8266 timeout derails

[gkunalupta]

I am trying to develop the esp8266 embedded c firmware for at commands with Atmega 2560 .... But on doing so i am getting the DATA OVER RUN ERROR again and again ...
So when i look at your source code i figure out one thing that u have used the TIME OUT thing with milis() for getting and recording the Response.
So is it important to use TIME OUT thing?
If yes then why and how did u find and assign the different time out parameters.