Mapping

hi all
i have established a vpn cisco 2620 router (local)to 2621 router(remote).
in side net work of 2620 is 10.10.10.xx

and remote private network is 10.10.20.xx.

i can ping from 10.10.10.xx to 10.10.20.xx.

i want to ping 206.70.70.xx and 205.70.79.xx.this two ip will be at remote site.

Please give me a suggestion that how can i ping both remote WAN IP from my local private network.if u give me the configuration i’ll be happy.

thankx