3Com Courier Reference

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3Com Courier Reference Manual pdf 99 page image

V.90 Capabilities 13-3If you enable the V.8 call indicate tone, expect to hear a sound like a fastringing signal while the call is being connected.V.34 If the remote device hasV.34 capability, the Courier V.Everything modeuses a line probing technique to determine the highest speed possibleunder current line conditions, then they complete the connection. If theremote device does not have V.34 capability, the Courier listens to thedevice's answer tones to identify the standard rate at which the remotedevice is operating, and then adjusts to that rate.When the Courier answers a call, it sends out a series of answer tonesignals until both devices negotiate the best connection rate.V.90 Capabilities The CourierV.Everything modem has V.90 capabilities. The CourierV.Everything modem can dial into V.90 servers to establish speeds up to 56 Kdownstream.Other Protocolsx2 x2 client modems can receive data at speeds up to 56 kbps and send dataat V.34 speeds. To use x2, the client x2 modem must connect to a serverx2 modem. If clients attempt to connect to ISPs that do not use x2, theclient modem will negotiate the next available modulation. For example,an x2 client modem calling into an ISP that only supports V.34, themodem will only negotiate the highest v.34 connection rate. Themaximum V.34 connection speed is 33.6 kbps.Fast Class (V.FC)HandshakingAfter trying V.34, the Courier V.Everything modem tries for the fastestpossible V.Fast Class (28.8 Kbps) connection. In order to negotiate V.FC,V.8 has to be disabled. V.FC is not part of theITU V.8 training sequence.If the remote device is not V.FC capable, a connection is made using thehighest compatible modulation scheme(V.32 terbo, V.32 bis, and so on,down to as low as Bell 103, or 300 bps)For your modem to CommandEnable V.90 ATS58.5=0 (Default)Disable V.90 ATS58.5=1