[Asterisk-Users] SIP + NAT question

[Ernest W. Lessenger]

I have a few questions regarding SIP and NAT that you may be able to 
answer. In both cases, I'm "assuming" that the customer will use SNOM 
phones and/or xten soft-phones.

Q1: I know that it is possible to use a STUN server to handle SIP over NAT. 
Does this require any special configuration of the NAT router? For example, 
will I need to configure port forwarding?

Q2: If I know the external port of the NAT router, and if I know that it 
will never change, do I still need a STUN server? In other words, can the 
SNOM and Xten (soft)phones be configured to know the proper addresses 
without discovering them through STUN?

Thanks,
--Ernest