Hi,
First of all, the problem you will face with 3G is IuUP. 3G adds, *inside* the RTP payload, another header and also mangles the AMR bits incompatibly, which we do not decode yet. That is why voice calls between 3G works (only because we forward the IuUP between the femto cells directly) and 3G <-> {2G,SIP} do not work. IuUP is supposed to terminate at the MGW.
We have a little bit of work started on IuUP, but it is still quite far from done and also has no high priority at the moment.
If you have a pressing need you could implement it or sponsor someone to do so. Let me know and I can give you some pointers.
Also, you need to set up external MNCC. Your mail hints osmo-sip-connector, so I assume you're doing that, but if you're not seeing *any* packages to/from SIP, then your MSC might still be doing internal MNCC.
No packets to/from Asterisk server, how can I fix this problem? Current documentation on osmo-mgw is quite difficult to understand.
The MGW is told by the MSC what to do, there is nothing you can configure there except the connection where the MSC talks to it. Think of it like a plain dumb switching board, and the operator plugging the cables is the MSC.
~N