Alternate destination call redirection for telecommunications systems

Abstract

This invention relates to apparatus and methods for redirecting calls from a first choice destination to some alternate destination if the call cannot be conveniently completed to the first destination. A call is initially extended through a toll network toward the first destination; if the toll network is congested and cannot reach an egress switch to access the first destination, or if a local exchange network connecting the first destination to the toll network is congested, or if a first destination PBX cannot be reached from the toll or local network because all access channels thereto are blocked, or if the first destination PBX is congested or attendants are unavailable, an indication that the call cannot be completed to the first destination is sent back to the ingress switch to the toll network for that call. The call is then redirected from the ingress switch of the toll network to an alternate destination. In some cases, this alternate destination may be the same as the first destination but accessed from a different egress switch of the toll network. Advantageously, this arrangement allows calls to be completed to an alternate destination regardless of the reason why the call cannot be completed to the first choice destination. If the first choice destination is a program-controlled PBX, the PBX can be programmed to reject certain types of calls according to the traffic load being handled by the PBX and the particular staffing available at a certain time. Thus, for example, the PBX could be arranged to accept calls for new orders but to redirect calls requesting information about shipments if the staffing of the first choice destination is relatively low. The reason for rejection can be used for altering the choice of an alternate destination or for canceling a potential redirection.