asterisk users - Apr 2005 - UDP Sip Data: GS Grandstream - remote office

Hello all,

Tried to get remote office working and found out that the GS Budge Tone 
100 takes the ip address inside the UDP packet data (SIP) that asterisk 
writes to.The Asterisk server is currently setup with a ADSL ZyXEL 
PRESTIGE 600 series router. My isp does dynamic ip assignment - so I 
cant tell asterisk what to write down in the sip packet as the ip 
changes on every reboot / day. I Have tried using a sip proxy and this 
caused only more confusion (sip proxy on same box as asterisk/ sip port 
forwarding and so on - messes up the LAN configuration).

So then I decided whether to use rp-pppoe or debians pppoeconf to make 
the Eth show the public ip address so that the GS Budge Tone 100 can 
then take the SIP ip address and then get is routed correctly accross 
the internet to the asterisk server. Did the whole thing only to realise 
that I have no idea if the router/modem is configured for bridge. So I 
spent the lat day and a half trying to get connected with the modem 
(even in windows XP) and still no connection.

So what I am asking is, has anyone had a similar issue. How did you 
solve it... and if anyone would like to help me just a bit (googled and 
still nothing) to allow the asterisk box to be awaire of the public ip.

-- 
Kind Regards
Etienne