Hi Zhigang, This is on purpose, oFono won't let you set the NoReplyTimeout if no NoReply condition is set. It is supported, but in the case of call forwarding, you must provide a SIA (phone number) otherwise oFono treats this as an invalid call forwarding request. What you're trying to do is register call forwarding no reply condition with no number, but a 30 second timeout. It makes no sense. Once oFono has meaningful support for these call types, then in some form, yes. But until then, there's no sense in exposing these features. Regards, -Denis