Sim800c http 604

I am using SIM800C,SIM800L,SIM808, Module and my application is based on HTTP ,And in india i am using vodafone SIM card ,All internet connectivity is fine .But while exciting HTTP GET request some half of time i am reviving “604” response .GPRS is connectivity is still present after reviving 601 it will start working again without doing anything.I want to execute my request with any error .I tried resent module using PWR key but still same issue .Is there anything i need to take care .to get rid “604” if i am having proper GPRS connected .

Getting the 60x errors is common on slow networks. Its a 2G device, you can expect server timeouts. So write handler in your code to resend if this occurs.