Could any kind soul please explain something to a total newbie.

I am considering getting the Samsung C460IP DECT VOIP phone. I already
have an account with voip.co.uk. I believe that the C460IP can be used
with the DHCP server in my ADSL Modem/Router to have an IP address on
my local network dynamically allocated. So far so good.

Having studied this group for some months I see posts about forwarding
some of the usual SIP ports to ATA's like the PAP2. Ports such as 5060
and 5061 seem common. If the Samsung phone obtains a dynamically
allocated IP address, is there still a need for port forwarding from
the router?

I can understand that if I give the Samsung phone a static address
then I can set the port forwarding in my router, but how does this
work with a local dynamic IP?

Thanks for any info.

Roger.