V.8bis suppression method and apparatus for modem relay

A method, comprising:

• monitoring a call during a voice mode phase for an initiating signal representative of a V.8bis transaction, wherein said initiating signal initiates the V.8bis transaction to identify and select a proprietary high speed modulation between first and second modems, said monitoring being performed by a local gateway associated with the first modem;
• if the initiating signal is detected during said monitoring, then suppressing the detected initiating signal in such manner that the initiating signal fails to reach both the second modem and a remote gateway that is associated with the second modem and that is incompatible with the detected V.8bis transaction and the proprietary high speed modulation;
• and whether or not the initiating signal is detected, then at the local gateway initiating a modem relay session of operation with the remote gateway, the modem relay session using a different modulation that operates independently of the proprietary high speed modulation;
• wherein the initiating signal is suppressed by the local gateway to prevent the first and second modems from communicating using the proprietary high speed modulation identified by the initiating signal.

An apparatus for initiating a modem relay session between a local and a remote gateway without V.8bis transaction interference, the apparatus comprising:

• a mechanism at the local gateway for monitoring a call during a voice mode phase for an initiating signal representative of a V.8bis transaction;
• a mechanism at the local gateway for suppressing such detected signaling such that the signaling does not reach the remote gateway, thereby preventing a modem from responding to the V.8bis initiating signal;
• and
• a mechanism at the local gateway for initiating a modem relay session with the remote gateway;
• wherein the initiating signal is characterized by a dual tone of defined frequency and duration;
• wherein the dual tone is at a frequency of approximately 1375 Hz and 2002 Hz and for a duration of approximately 400 ms.

A computer-readable medium containing a program, the program comprising:

• instructions for monitoring a call for signals originating from a first modem and received over a circuit switched network, the signals initiating a predetermined high speed modulation that provides a transfer rate of 32 kb/s or more between the first modem and a second modem;
• instructions for detecting whether the signals include a predetermined dual tone that identifies the signals as negotiating the predetermined high speed modulation, the predetermined dual tone occurring at a frequency of approximately 1375 Hz and 2002 Hz and for a duration of approximately 285 ms to 400 ms and occurring before an answer tone for the monitored call;
• and
• instructions for blocking the predetermined dual tone from entering the packet switched network to prevent the second modem from responding to the predetermined dual tone thereby preventing the modems from negotiating the predetermined high speed modulation for the monitored call.

An apparatus for initiating a modem relay session between a local and a remote gateway without V.8bis transaction interference, the apparatus comprising:

• means at the local gateway for monitoring a received call for signals originating from a first modem and received over a circuit switched network;
• means at the local gateway for observing a predetermined dual tone in the signals, the predetermined dual tone occurring at a frequency of approximately 1375 Hz and 2002 Hz and for a duration of approximately 285 ms to 400 ms and occurring before an answer tone for the monitored call and the predetermined dual tone identifying the signals as being a type associated with a predetermined high speed modulation;
• means at the local gateway for suppressing such predetermined dual tone such that the observed predetermined dual tone does not reach the remote gateway, thereby preventing a second modem from responding to the identified signals with a predetermined high speed modulation compatibility response;
• and
• means at the local gateway for initiating a modem relay session with the remote gateway, the modem relay session operating independently of the predetermined high speed modulation.

A method of operating a local gateway that separates a circuit switched network and a packet switched network, the method comprising:

• receiving a call originating from a first modem over the circuit switched network;
• transmitting the call over the packet switched network to a remote gateway for forwarding to a second modem that is located in a same or another circuit switched network;
• monitoring the call for signals originating from the first modem and received over the circuit switched network, the signals configured to establish a predetermined high speed mode of operation that operates independently of V.90 and provides a transfer rate of 32 kb/s or more;
• determining whether the signals include a predetermined dual tone that identifies the signals as being configured to establish the predetermined high speed mode of operation, the predetermined dual tone occurring at a frequency of approximately 1375 Hz and 2002 Hz and for a duration of approximately 285 ms to 400 ms and occurring before an answer tone for the monitored call;
• and
• blocking the predetermined dual tone from entering the packet switched network to prevent the monitored call from operating according to the predetermined high speed mode of operation.