What are the actions for a ISP to realize a VPN connexion ?

[egrellet]

When you connect two Routers with VPN , and between these two routers, you have INTERNET, what are the actions to do for the provider (ISP) ?

We want use a Frame-Relay connexion between our router and the ISP.

Thanks for your answers.

[nicholas.monro]

I have also had difficulty with my ISP about opening

up the correct protocols & ports for VPN Tunnels.I discovered that in addition to Ports 50 ESP & 51 AH

that I needed to ask them to open UDP 500 ISAKMP.

Hope this helps.

[egrellet]

Thank you for your answer.