IP authentication with a SIP provider? Calls not working

We just started using VoipInnovations as a SIP provider. I called tech support for documentation on how we add them as a trunk in our FreeBPX system and they keep saying that all we need to add is host=xxx.xxx.xxx.xxx. I have never seen this before. Most sip providers have a bunch of settings, ie:

host=provider ip address
username=userid
secret=password
type=peer

Has anyone else come across this, or know how this SIP trunking works? I managed to get outgoing calls working, but incoming do not. I tried a bunch of combinations in the trunk settings and this is what we currently have:

type=peer
allow=ulaw
host=switchIP
username=blabla
secret=blabla

We are about to sing up with VoipInnovations. Did you have a chance to get this resolved?

How is their service?

Thank You