Vadim Yanitskiy vyanitskiy@sysmocom.de wrote:
[changing order slightly]
Just to clarify: currently when you invoke the silent-call command, no Call Control signalling is happening at all. Only paging and then the RR Assignment procedure. Strictly speaking it's not really a "call", just a channel assignment without any further commands.
I know, I read the code.
As I already mentioned, the existing silent-call command is a bit special in a way that it allows to select a specific TCH rate (full or half) and a specific codec (if needed). The test-call command I proposed can by implemented on top of the existing silent-call logic.
And how exactly do you propose implementing an actual MT call (with MT SETUP CC message to MS) on top of this silent-call logic? The moment you send that MT SETUP message to an MS, that MS will respond with CALL CONFIRM and other CC messages to follow - how are you going to handle them? You will need at least some handling of CC messages from MS: if the MS sends DTMF start, call hold or call modify messages, the network MUST respond with either ACK or REJ, and then of course there is graceful call disconnect and clearing. Likewise in the case of vty- initiated "hang up" of these test calls, you will also need to send CC DISCONNECT toward MS and then follow subsequent graceful call clearing sequence. I invite you to look at the source for themwi-test-mtc as an example.
Looking at the code in OsmoMSC, it looks to me like a lot of work to implement the above, given that the current code merely translates between A interface CC messages and MNCC.
M~