Hi Neels,
On Tue, Mar 12, 2019 at 06:47:43AM +0100, Neels Hofmeyr wrote:
The really interesting part then is the 24.007 11.2.3.2 N(SD) sequence number patching. Took me a moment to realize that when the one BSC wants to send CC DTAP while the other has advanced in N(SD) sequence numbering, the DTAP sent from TTCN3 is rejected as duplicate because TTCN3 has lost the MS state. So some way or other .. we need to manually tweak the TTCN3 N(SD) state to match the actual DTAP flow, or keep a common MS state in TTCN3 that sorts this out across BSCs.
That's another indication that somehow the component architecture of the test isn't right.
Either one goes for the "single component with two BSSAP ports [one for each emulated BSC]" approach I suggested in my previous e-mail, or one has to separate the "simulated MS component" from the "simulated BSC component". This way you could "disconnect" a test port between the MS and BSC0 and re-connect that port to BSC1, while the MS component retains all of its state. Sounds more complex to implement than the "single component with two BSSAP ports" approach.
Regards, Harald