Hi Neels,
one more comment:
On Sun, Apr 03, 2016 at 10:05:07PM +0200, Harald Welte wrote:
I therefore think the HNB-GW should try to look only like a single RNC to the MSC, and very clearly only a single RANAP Reset should be sent.
One further reason: The RNC-ID only has a range from 0..4095, i.e. if every hNodeB was identified by a separate RNC-ID, you could never have more hNodeBs in your entire network. For public telco networks, 4096 hNodeB (and no macro network!) is certainly not sufficient. That's certainly not how the system was designed. So the HNB-GW serves a similar purpose as the osmo-bsc_nat: To hide many (hnb-internal RNCs) towards a CN element, so the CN element thinks it only deals with very few of them.
In fact, a typical "many co-located OsmoBTS+OsmoBSC" talking to bsc_nat is the exact correspondence to the hNodeB (NodeB+RNC) talking to HNB-GW setup in UMTS. With the big difference, that in the UMTS case, there is a specification for such as system, and in the GSM space, it is something that only exists in the Osmocom implementation.
Regards, Harald