MSN in chan_dahdi


Today I have connected PRI card TE 122 with our national PSTN operator (ISDN).
This operator has not actually new hardware, but if we one time do connecting it’ll be worked fine and very long time.

During our setting technical specialist from operator side asked me about how will system behaves and which hangupcause he can see if I don’t write DID number in Asterisk diaplan? We have tried and I don’t write any pattern. Everything was ok. But after some time I have saw in chan_dahdi.conf some possible setting - it’s “msn”. I used it, but when I don’t write MSN, in cli I see that channel has send to originator side message destroy, but call is continuous some time.

Is it normal behavior? I think isn’t. How can the system really drop or cancel the call?