* Upstream has a separation of BTS and NET side for RTP ports and
can allocate them dynamically.
* Upstream has gained the concept of trunks. We will now have various
trunks to connect audio things.
* We will now be able to utilize multiple trunks and have the endpoints
used properly.
This new interface allows to have multiple linksets, msc
connections and ways to connect those in one instance of
the osmo-stp. Forbid to reset linksets without an app.