Abstract: A method for determining characteristics of a data communication channel between first and second data communication devices. The method includes the step of sending a relatively low power digital probe signal over said channel from said first to said second data communication devices. The method further includes sending a second digital probe signal corresponding to an analog signal having a relatively high-frequency signal with a time-varying dc component from said first to said second data communication devices. The second data communication device receives a signal, said received signal corresponding to said probe signals sent by said first device. In addition, the second data communication device determines whether said received signal varies from a predetermined standard.

Abstract: A method of processing incoming digital telephone calls from remotely located call originators which are destined for receipt by a host computer system. The host computer system is linked to the telephone network by a network access server. The call originators may be any type of data terminal, such as a personal computer or a credit card swipe, which is connected to a modem. The network access server extracts control signals imparted onto the telephone line and correlates the control signals with particular communications, routing or applications protocols identified with the call originators. The modem in the network access server which answers the call is configured during the call connect process and placed in a compatible format for the communications protocol of the incoming call. This dynamic custom configuration of the modem reduces the overall telephone call connection and processing time.

Abstract: A method of processing incoming digital telephone calls from remotely located call originators which are destined for receipt by a host computer system. The host computer system is linked to the telephone network by a network access server. The call originators may be any type of data terminal, such as a personal computer or a credit card swipe, which is connected to a modem. The network access server extracts control signals imparted onto the telephone line and correlates the control signals with particular communications, routing or applications protocols identified with the call originators. The modem in the network access server which answers the call is configured during the call connect process and placed in a compatible format for the communications protocol of the incoming call. This dynamic custom configuration of the modem reduces the overall telephone call connection and processing time.