Need help connecting to VoIP provider

[illuminatus]

This is ALL the information I have from our provider:

Our phone number is: 214-329-4838
That phone number is bound to our IP address: 65.189.246.156
Our Providers IP address is: 209.120.255.14

AND

There is no registration necessary. I will send an invite and 65.189.246.156 just needs to accept it from 209.120.255.14.

Currently, this is how I have the SIP trunk setup:

@sip.conf

[general]

port = 5060 ; Port to bind to (SIP is 5060)
bindaddr = 0.0.0.0 ; Address to bind to (all addresses on machine)
disallow=all
allow=ulaw
allow=alaw
context = from-sip-external ; Send unknown SIP callers to this context
callerid = Unknown
externip=65.189.246.156
localnet=192.168.1.0/255.255.255.0

[209.120.255.14]
username=2143294838
user=2143294838
type=peer
secret=
insecure=very
host=209.120.255.14
context=from-pstn
canreinvite=yes

[pstn]
username=2143294838
user=phone
type=user
nat=yes
host=209.120.55.14
fromuser=2143294838
canreinvite=no

Anyway, for a bit I had there I had outgoing calls working. However, 2 way communication didn’t work. I could be heard but not the other way around.

The provider isn’t being much help. Any ideas?