To make outbound calls to some of the gateways you need the fix for this bug.
http://bugs.digium.com/view.php?id=3609

Tech. support at Ravon/MDCI was very helpful in tracking this down for me. Thanks Jordan.(:biggrin:)

The config below almost works. Specifically:
1. Incoming calls work well.
2. Outgoing calls work to some of their gateways. Calls to Cisco gateways are dropped after 15-20 seconds (no sip debug messages). Any idea why? The same gateways work with X-Lite.
3. I don't think all the references to mutiny.mdci.ca are necessary in my config, but I don't know which was the one which made it work. Their proxy is sensitive about the name. The IP address does not work, nor do the other hostnames they use for that server.

Tech support has tried to be helpful. No complaints, yet.

sip.conf:
register => :@mutiny.mdci.ca

mutiny.mdci.ca
type=friend
username=
fromuser=
secret=
context=ravon
host=mutiny.mdci.ca
fromdomain=mutiny.mdci.ca
incominglimit=1
outgoinglimit=1
insecure=very
qualify=no
canreinvite=no

extensions.conf:
ravon
exten => ,1,Goto(,s,1)
exten => ,2,Hangup

Just a warning about a business practice they have used in the past.

This company spammed my domain. They scraped the addresses from an email with multiple recipients in the To: line and spammed them all with advertising for this ravon service.

Ravon agreed to give me the necessary information to get me registered on my Asterisk box.
I can now dial out through Ravon via my Asterisk box.
The Ravon adapter is disconnected, and I'll try to return it and avoid the rental-fee.
Ravon is currently the only one of two providers that can port Canadian numbers and provide free local calling for under $20/month.
I'll get back to you all when my number is ported and the incoming calling is working.

Hi guys,

I'll be the guinea-pig using these guys service.
After a few e-mails back and forth with someone who knew what I was talking about, I was assured that I could configure the service on my own box (*). They're using SIP v.2 he told me.
A week after ordering, I got the (used/refurbished) Grandstream-486 adapter. I plugged it in, behind my firewall, and it worked right away. However, they locked the web interface to the adapter, so I couldn't get on it. I spoke to the provisioning tech, and after some time, he understood what I needed. I needed the SIP username/password and the SIP server name. He was going to talk to his managers, and get back to me today.

Haven't heard from them yet, but the same guy I dealt with pre-sale, forwarded my question to some senior tech's.

Will get back to you all about my experience.

For now I daisy-chained an SPA-3000 with the Grandstream, and I can make outgoing calls that way.