Abstract: A switch-adjunct integration device uses multiple line appearances of one or more digital telephone lines to gather information on calls destined for an adjunct voice-mail system, to transfer the calls to analog phone lines leading to the voice-mail system, and to detect call completions. Call completion is detected by bridging some of the line appearances to the analog phone lines and monitoring the bridged line appearances for call status reported thereon by the switch. Call-related information, including call completion, is reported from the integration device to the voice mail system over a control link. The analog phone lines are connected to the voice mail system through switch relays on the integration device. The integration device momentarily opens a relay when it detects call completion on the connected analog line to further enhance call-completion signaling.

Abstract: An arrangement that enables an adjunct processor to determine the service status of switching system communication ports to which the adjunct processor is connected, without reliance on switch-to-adjunct status-conveying messages. In-service and idle ones of the ports participate in calls on a rotating basis. Following receipt of N calls, where N is the number of in-service ports connected to the adjunct processor, the arrangement determines whether each port that is presently designated as being in-service and idle has participated in one communication before a port has participated in a second communication. The arrangement then treats as out-of-service any port presently designated as being in-service that has been so determined a predetermined number of sequential times. It also selectively designates as in-service ports that have participated in communications since the last determination had been made.

Abstract: To provide robustness within the SMSI data communication protocol, a voice message system stores all message-waiting update (MW) messages that it sends to a communication switching system, and periodically transmits a properly-formatted MW message bearing intentionally-corrupted data to the switching system over their connecting data link. After each transmission the voice message system awaits the return on the data link of an invalid message-waiting (IMW) message. If the IMW message is returned within a predetermined time period following transmission of the corrupted MW message, the voice message system treats the data link as viable and clears the stored MW messages. If the IMW message is not returned within the predetermined time period following transmission of each of two corrupted MW messages, the voice message system treats the data link as not viable and, following repair of the link, re-sends the stored MW messages to the switching system.