not working for me

[fab]

I live in the US and I have Vonage as my SIP provider. my telephone
application on my iMac is not working, I need your help.
Under account information, I inputted my account info,
domain=sphone.vopr.vonage.net, and my username and password. (is this
the username and password that I use to login to www.vonage.com
website?)
Under the advance section, the sip address was propagated so it was
the registry server. I did not check the "substitute" box or
"connecting using proxy" box.
I did not put anything on the network section, it already has a local
sip port number, no stun server, it has port number, no outbound proxy
and it already has a port under that. both ICE and DNS SRV are not
checked.

what else do I need to do? any ideas?