ASUS are the masters of failsafe code
Let's think about that brilliant code behind ...
otp = RANDOM_INT(6)
user.session.otp = otp
if sms.gateway.isAlive():
sms.gateway.send(user.number, otp)
else: // hm good question, I have a brilliant idea :D
user.session.html = "We are facing a SMS issue. Please use %s as your OTP" % otp