Hello Marcel, On 12 Jan 2011, Marcel Holtmann wrote: > Are we expecting that all modems will just establish a normal voice > call > and only later on signal that it is a TTY call? Any input from > different > vendors other than IFX. What about STE, ISI?
not later, but as part of standard call setup. E.g. on ISI, CTM is a property of a voice call. And this makes sense as TTY calls _are_ essentially voice calls, with just a bit indicating to the network that the voice circuit should be free of any transcoder/audioprocessing/etc that is not compatible with CTM. And this is negotiated as part of standard call setup (same way as supported codecs). My understanding so far has been that TextTelephony.Enabled=TRUE means that the CTM bit is set in all subsequent MO calls, and it is set by default when answering to MT calls. And the one special case is receiving a CTM-enabled call when TTY is not enabled (in oFono). In this case it should be possible to enable TTY (for at least that call) and respond to the call (and ifxmodem seems to provide support for this scenario). This should be standard stuff to all modems as this is a heavily regulated feature. _______________________________________________ ofono mailing list ofono@ofono.org http://lists.ofono.org/listinfo/ofono
