Asterisk server behind DHCP NAT

hi all of friends
i want to host asterisk server behind DHCP NAT. Is this possible? And how can i do this. Next, i want to know how to configure sip client like ekiga phone, when asterisk server behind nested NAT.
i mean NAT behind NAT. Please help me.

I haven’t tried this, and would advise using a more business friendly ISP, but no-one else is replying. I believe the preferred method is to use a STUN server on the public side. You might also get away with using externhost and a dynamic DNS server.

If the double NAT is visible to the VoIP system, you should try to eliminate it. If you can’t do so, I think the best option is to run a SIP proxy on the inner NAT router.

If there is nothing of VoIP significance between the two routers, it may be possible to treat them as a single NAT stage.

As you presumably control the inner NAT, you should ensure that inner local addresses are (preferably) static, or at least are not changed unless the lease has gone unrefreshed for an extended amount of time. Do not do what some ISPs do and gratuitously change the address on a refresh.

PS. I’m assuming that NAT behind NAT means public side to private side. Public side to public side should be easier if the Ekiga is NAT-aware.