Cisco Technology, Inc.

Gavin Jin

Herbert Michael Wildfeuer

Mehryar Khalili Garakani

Chieh-Wen Tsai

In one embodiment, one or more gateways sniff the voice channel during the voice mode. If it is determined that V.8bis signals are being initiated, then the gateway breaks these exchanges by suppressing such signaling. Modem relay communications then are allowed to proceed. Briefly, the method and apparatus involve monitoring a call during a voice mode phase for an initiating signal representative of the defined signaling, the monitoring being performed by a local gateway and, if such an initiating signal is detected during the monitoring, then suppressing such detected signaling in such manner that the signaling does not reach the remote gateway. Preferably, the monitoring is for an initiating signal characterized by a dual tone of defined frequency and duration of approximately 1375 Hz and 2002 Hz for a duration of approximately 400 ms or 285 ms, in agreement with the ITU-T Recommendation V.8bis (standard) adopted by the International Telecommunication Union. Monitoring is continued at least until an answer back from an answering station is received by the gateway. When the suppression succeeds and the remote (non-initiating gateway that may be awaiting such an initiating signal halts any further V.8bis transaction attempts, the local gateway initiates a modem relay session of operation with the remote gateway.

Suppressing high speed modulation negotiation

A method for establishing a high-speed modem relay connection over a voice frame network between an originating modem with an associated calling-leg gateway and an answering modem with an associated called-leg gateway is described. The method includes determining at a predeterminedly early time during end-to-end physical layer negotiations between the originating modem and the answering modem whether both modems are high-speed modems, with the determining being performed by one or more of the associated gateways. If so then the method further includes terminating end-to-end physical layer negotiations between the originating modem and the answering modem, with the terminating being performed by one or more of the associated gateways. Finally, the method includes negotiating local physical layer on either end of the connection between the originating modem and the calling-leg gateway and the answering modem and the called-leg gateway. By this method, the calling-leg gateway serves as proxy for the answering modem and the called-leg gateway serves as proxy for the originating modem. Modem relay connection apparatus for use in a voice frame network gateway to establish a data channel between two modems is also described. The apparatus includes an amplitude-modulated answer (ANSam) tone detector; a signal suppression mechanism responsive to said tone detector for suppressing signals between the modems to terminate end-to-end negotiation between the two modems; a code detector for detecting a digital call menu (CM) code responsive to an amplitude-modulated answer tone; and a proxy negotiation mechanism responsive to said code detector for negotiating a local physical layer between the gateway and a local one of the two modems.

High-speed dial-up modem session startup method and apparatus

The invented method involves one or more gateways sniffing the voice channel during the voice mode. If it is determined that V.8bis signals are being initiated, then the gateway breaks these exchanges by suppressing such signaling, thereby avoiding the above-described detrimental effects. Modem relay communications then are allowed to proceed. Briefly, the method and apparatus involve monitoring a call during a voice mode phase for an initiating signal representative of the defined signaling, the monitoring being performed by a local gateway and, if such an initiating signal is detected during the monitoring, then suppressing such detected signaling in such manner that the signaling does not reach the remote gateway. Preferably, the monitoring is for an initiating signal characterized by a dual tone of defined frequency and duration of approximately 1375 Hz and 2002 Hz for a duration of approximately 400 ms or 285 ms, in agreement with the ITU-T Recommendation V.8bis (standard) adopted by the International Telecommunication Union. Monitoring is continued at least until an answer back from an answering station is received by the gateway. When the suppression succeeds and the remote (non-initiating gateway that may be awaiting such an initiating signal halts any further V.8bis transaction attempts, the local gateway initiates a modem relay session of operation with the remote gateway.

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Santa Barbara, CA, United States of America

Gavin Jin