S1AP_Emulation: improve accessibility of unit-data

When S1AP unit-data is passed around, there is always the problem that
it is routed to the MTC_CT. The reason for this is that S1AP_Emulation
cannot determine a specific receiver component because unit-data does
not contain any addressing fields that would identifiy a specific eNB or
UE.

Unfortunately it can be a huge problem when developing test fixtures
that use unit-data from inside a ConnHdlr component. It is no problem to
send unit-data using S1AP.send(), but it is impossible to receive
unit-data through the same path.

The solution that is proposed in this patch uses a mechanism that allows
to create an expectation for a specific procedureCode. When the
S1AP_Emulation sees a messages with the expected procedureCode, it will
forward it to the ConnHdlr component.

Related: OS#5760
Change-Id: I041b45b247e365b0d4ee8645c07dc5f26007af82
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M library/S1AP_Emulation.ttcn
1 file changed, 110 insertions(+), 1 deletion(-)