[asterisk-users] Receiving SIP calls without registeration and dynamic IP address

[Jared Smith]

On Thu, 2007-08-02 at 08:11 -0700, bilal ghayyad wrote:
> How can I configure asterisk to receive a call from
> SIP end point without being registered at asterisk and
> its IP address is dynamic, and authentication to be
> based on the username and password or any other
> string?

I think you're confused here... registration has nothing to do with a
SIP device being able to send calls to Asterisk.  A SIP devices
registers with Asterisk so that Asterisk knows where to send calls going
*to* the device.

For calls coming into Asterisk, the SIP channel driver first looks at
all the users in sip.conf (you know, everything set with type=user or
type=friend).  It matches on the name in square brackets as the SIP
username, and the password on the "secret=" line.  If the device
authenticates correctly, the call gets sent to the dialplan in the
context specified by the "context=" line.

As an example, let's say we had the following in sip.conf:

[test]
type=user
secret=abc123
context=hamburger

If any SIP device were to come along and authenticate with the username
"test" and the password "abc123", Asterisk would accept the call and
send the call to the [hamburger] context in the dialplan.  Asterisk
would do this *whether or not* the device had registered.

Now, as I understand it, if Asterisk can't find any users (or friends)
that match, it then goes looking through the list of peers, trying to
match the "host=" field to the IP address of the device that's sending
the call to Asterisk.

Hopefully that clarifies things for you.


-- 
Jared Smith
Community Relations Manager
Digium, Inc.