[Serusers] NAT asterisk-ser

I have a scenario where an asterisk machine is working with 2 network cards (1 public and 1 private). My IP phones are all on private Ip’s It works great internally but I cannot forward sip traffic to a voip provider due to NAT. I tried to install SER on the same machine using different ports so the asterisk forwards all numbers starting with 00 to SER. SER will be forwarding these calls to a voip SIP provider. Can anyone provide me with a sample config for SER cause when ever I try to send a number starting with 00, I get a sip error that the number does not exist. Regards Chris --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.801 / Virus Database: 544 - Release Date: 24/11/2004