(Trying TLDR as asked)
Does anyone here happen to live in a country where at least one public
GSM network is known to still operate with traditional T1/E1 TRAUs? I
would like to try making an international call from my G.711 VoIP
system in USA to a GSM MS in whatever country that is served by a
traditional TRAU, and see if I can detect TFO in-band signaling within
the G.711 PCM sample stream coming from the far end. Or if someone
knows for certain some solid technical reason why this idea is doomed,
I would appreciate that explanation too.
Reason for my interest: I have a desire to implement GSM 08.62 or 3GPP
TS 28.062 TFO, and of course publish the source under a public domain
license, but the protocol is complex enough to where I don't see any
feasible way to test for correctness other than through actual
interoperability testing with an existing implementation.
M~
