public override async Task StartDtmf(string k)
{
int i = -1;
if (!int.TryParse(k, out i))
{
if (k == "*")
{
i = 10;
}
else
{
i = 11;
}
}
var source = new CancellationTokenSource(10000);
await Task.Run(() =>
{
_sdkLib.sendDtmf(_sessionId, DTMF_METHOD.DTMF_RFC2833, i, 160, true);
}, source.Token);
}
