Information input/output controller for telephone lines

Abstract

The invention converts information input from either a charge line or a non-charge line to data form and then stores it in a memory device along with identification data specifying the type of line on which the information was received. It also reads information from the memory device in response to information read requests received by way either of a charge line or of a non-charge line and, when called upon to output said information either to a charge line or to a non-charge line, it inhibits the output of the information to a non-charge line in cases where the line indicated by the aforementioned identification data and the line on which the information read request is received are both non-charge lines. This enables either the sending party or the receiving party of a service, but not both, to be charged for the service while at the same time ensuring that, if the sending party and the receiving party of the service both use a non-charge line, the output of the information will be inhibited in order to preserve the integrity of the charging function. Moreover, if the line indicated by the identification data and the line on which the read request is received are both charge lines, a message is sent to the issuer of the read request to indicate the availability of a non-charge line. This prevents the sending party and the receiving party of the same service from both being charged for the service.