[Asterisk-Users] Trunk SIP howto ?

[Noc Phibee]

Hi

anyone know if a Trunk SIP howto are created ?

I have 8 VoIP account with for all 1 login/pass per number.
i want add into my asterisk but not know where ;=)

Other questions:

my supplierhave a dns:    sip.phonesystems.net
this name have 2 IP address
it's not a problems for Asterisk that he have registred on
the first ip address and receive information of the second ?

Thanks for your help