>Has your ISP changed its service?
>
>- periodic loss of service could be the ISP changing your IP address (if you have a dynamic IP). If that's the case your network equipment (e.g. router) probably needs to be configured to use DHCP to pick up the new IP address when it's changed. Maybe your ISP has started to change its dynamic IP customers more often
>
>- poor-quality firmware in some low-cost broadband routers can cause periodic disconnects. Sometimes this is caused by a short DHCP lease. Typical leases are 24 to 48 hours; leases of 4 hours or less are often unreliable. If your external IP uses DHCP, check the remaining lease time (typically look at the Status page, WAN information). If this is a problem, updating the router firmware may help
>
>- maybe your ISP has started blocking ports and/or protocols, and a side-effect might be VPN failure
>
>- have you, at any point, rebooted your infrastructure e.g. broadband modem, router(s), switch(es) etc.?

This is done through phone lines, so we have to use the PPP approach. If that would be cable, DHCP would be used. I did tried it however and that gives a no connection.

Also, it works for other laptops on my network either connected directly or wireless. So, it means the router and the linksys are ok.