This will guide you on setting up an outgoing trunk for Bandwidth.com. There is no trunk needed for inbound calls since they send the calls in this format: +17185551212@0.0.0.0 where +17185551212 represents your phone number ad 0.0.0.0 represents your IP Address.

I live in New York so I am showing you how to set up the trunk using the Eastern server as the primary route. You may change this.
Remember, if you get "all circuts are busy", go to the next method. Not all of them will work for you.
Method A will most likely NOT work with asterisk 1.4 users

For all methods, make sure that in the Dial Rules for EACH trunk, there is a line containing:
011.|
since bandwidth.com doesn't pass calls with the 011 prefix

Method A:
Trunk 1:
Trunk name: Bandwidth-Maryland
Outgoing dial prefix: +
PEER Details:
type=peer
port=5060
nat=yes
host=216.82.224.202
dtmfmode=rfc2833
disallow=all
canreinvite=no
allow=ulaw

Trunk 2:
Trunk name: Bandwidth-Georgia
Outgoing dial prefix: +
PEER Details:
type=peer
port=5060
nat=yes
host=4.79.212.236
dtmfmode=rfc2833
disallow=all
canreinvite=no
allow=ulaw

Trunk 3:
Trunk name: Bandwidth-California
Outgoing dial prefix: +
PEER Details:
type=peer
port=5060
nat=yes
host=216.82.225.202
dtmfmode=rfc2833
disallow=all
canreinvite=no
allow=ulaw

Method B:
Trunk 1:
Trunk name: Bandwidth-Maryland
Outgoing dial prefix: +
PEER Details:
dtmfmode=rfc2833
host=216.82.224.202
type=peer
disallow=all
allow=ulaw

Trunk 2:
Trunk name: Bandwidth-Georgia
Outgoing dial prefix: +
PEER Details:
dtmfmode=rfc2833
host=4.79.212.236
type=peer
disallow=all
allow=ulaw

Trunk 3:
Trunk name: Bandwidth-California
Outgoing dial prefix: +
PEER Details:
dtmfmode=rfc2833
host=216.82.225.202
type=peer
disallow=all
allow=ulaw

Method C:
Trunk 1:
Trunk name: Bandwidth-Maryland
Outgoing dial prefix: +
PEER Details:
dtmfmode=rfc2833
host=216.82.224.202
type=peer

Trunk 2:
Trunk name: Bandwidth-Georgia
Outgoing dial prefix: +
PEER Details:
dtmfmode=rfc2833
host=4.79.212.236
type=peer

Trunk 3:
Trunk name: Bandwidth-California
Outgoing dial prefix: +
PEER Details:
dtmfmode=rfc2833
host=216.82.225.202
type=peer

In outbound routes, here is my order:

Route name: Out
Dial Plan:
1NXXNXXXXXX
011.
911
411

Trunk sequence:
0: SIP/Bandwidth-Maryland
1: SIP/Bandwidth-Georgia
2: SIP/Bandwidth-California

And that's all
Please e-mail me or post a topic on the forums if you encounter any problems