We see this from different points of view. :)
We're interested to show
possible
ways of OpenBTS interoperability with more conventional BTSes like ones
OpenBSC use and evaluate problems which will arise there. But we want to
show this with "flat IP" network instead of burdening OpenBTS with
A-bis interface.
There is A-bis over IP of course :)
Because just connecting them with asterisk just proves asterisk works, you
still have two independent GSM network.
A better integration would allow roaming between an openbsc/nanoBTS|BS11
and a OpenBTS. That would be pretty cool.
Now that can be done either by OpenBTS having a Abis-over-IP IF (much like
the nanoBTS), or by implementing inter-msc roaming in both (I think, didn't
check deeper).
I must admit I don't personally think it's ideal to have the BSC/MSC/HLR...
layers duplicated in both OpenBTS/OpenBSC. It's pretty common in opensource
to have several project 'doing the same thing' and it usually helps
innovation and such but in this case there aren't thousands of developers
with good GSM knowledge ... OTOH, OpenBTS and OpenBSC have made some choice
that don't make a seamless reuse of code trivial (C vs C++, single vs multi
thread). The licenses are compatible that's a start :) (v2 or later vs v3)
Anyway, just my 2cents.
Sylvain