A method of call control in which a first communications network, detecting calls directed to a destination in the first network; redirects at least some of the calls to a destination in a second network (e.g. on no answer from the destination in the first network). The first network then operates in two phases. In a first phase, for a group of calls redirected to the second network, the time delay before the call is answered in the second network is recorded. When a number of time delays have been recorded, a delay period is set to a value less than the maximum value of the recorded time delays. In a second phase, for a second group of calls redirected to the second network subsequent to the calls of the first group, when a call of the second group is not answered in the second network within the delay period, the call is redirected to a message service associated with the first network.