mDot Class C fails to receive after 20min

Dear all,

I am trying to send 1 packet every 4 seconds from a conduit Multitech gateway to a dot configured in class C.

The conduit sends the 1byte payload packet every 4 Sec indefinitely.

For the first 20min (sometimes it’s 15 min sometimes 1 hour), the mdot gets the message but suddenly stop receiving packets.

Am I missing something? Is it expected? What should I do to receive packet indefinitely?

Thanks!

Steeve