I'm currently setup the superdial already. But it just seems take a while (~5 - 10 sec) to check if the truck is "failed". So, for that 5 - 10 sec, I got "dead air" on my phone. Then I will get ringing tone again once it jumped to the working trunk. That's why I try to eliminate the dead air.
It is not normal to take more than 5 seconds for checking. In my case, I have set 8 different trunks in different devices. It takes about 3 to 5 seconds to determine the available trunk to dial out.
My trunks inlcude ATAx2, DAHDI, OBi110, OBiApp, 2bApp, USB Dongle and IP01.
Are you using the same SuperDial script as ckleea and I are using?