VPN connection dropping

I work from home and connect to my company's server with a VPN connection. I've been having problems with dropping the connection and then within a few minutes the connection is restored. When I talk to the tech people at work, they said if VPN senses any change or reduction in band-with, the connection will drop and then restore, and the problem is with my ISP/modem/router. I noticed that the link light on the modem is flashing yellow. What do I do to correct the dropping of the connection? Thanks