Paul De La Rosa writes: > Is there a way with pppd to send the '+++' command to temporarily switch > out of data mode into command mode. I'm using a Siemens tc63 module and > I need to check signal strength every now and then but I was trying to > avoid bringing down the whole ppp0 interface to do that check. I tried > spawning pppd as a child process using the same file descriptor as the > parent so the parent could send the mode switch and signal strength > commands but it seems that pppd is reading the data that is returned > before the parent got it. This is something that's been discussed a few times. In order to do it "right," you'd need to modify the PPP kernel driver to do this work, so that you don't accidentally stomp too much on packets in flight. A slightly better way to do this (rather than the Hayes TIES signal) is to use the enter-command-mode-on-DTR-drop configuration for the modem, and then use that to switch back and forth reliably between data and command mode. It still requires driver involvement, and it also requires explicitly doing ATH to hang up (rather than just closing the device), but it's much more reliable. Better still is to get a commercial-grade modem that has a separate performance monitoring interface. That's what we ended up doing when I was at Bay Networks; all of the other in-band methods of signaling are mere hackery in comparison. -- James Carlson 42.703N 71.076W <carlsonj@xxxxxxxxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-ppp" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
