/SWITCH=switch-character

    Specifies a character sequence that you can use to switch the
    line to PPP mode. To activate PPP mode, type Ctrl/switch-
    character. You can select any ASCII character from @ though Z,
    except C, M, Q, S, and Y. The default switch character is @.

    Similar to the CONNECT command, this qualifier switches a
    line into PPP mode. If the packet negotiations fail, PPPD
    exits and the line is left in terminal mode. If line is set to
    /MODEM and /NOHANGUP, this can result in extraneous data, the
    ASCII representation of Internet Protocol (IP) packets, being
    transmitted across the open line.