Internet connectivity problem

I have ZTE 831all modem and BSNL internet plan of multiuser.
That configured as first lan cable come from modem to Network Switch of NetEGear of 24 port where all network user is connected and using internet. But problem is that in a day internet is lose the connectivitythree or four time with modem means i am not able to ping 192.168.1.1 from any connected system with Network switch.

Whisch is solved after only restart of modem.
Please help me.

Thanks in advance.