Matt,

On Wed, Dec 06, 2017 at 04:10:21PM -0600, Matthew Jordan wrote:

> 1. Proxy REGISTER requests through to Asterisk, allowing Asterisk to
> (believe) it is the Registrar
>
> In this particular case, you'll need a PJSIP endpoint for each SIP endpoint
> that is registering. Identification will need to be done based either on
> the From user or by a custom header that Kamailio can add and pass off to
> Asterisk. You will need to use the outbound_proxy options so that outbound
> requests go through Kamailio as opposed to directly to the registered
> endpoints. The benefit of this is that it gives Asterisk all of the
> information it needs, all of the time. The downside is that you now have
> potentially many services acting as a Registrar, and you have a lot of
> traffic flying around that you don't need or want.

Can't a lot of the complications here be obviated through Path?