Hi I'm trying to connect a USB CDMA modem (z010) to a CentOS 4.1 (kernel 2.6.9-11.EL) and I can't talk to the modem. I tried the same modem under Fedora Core 1 (2.4.22-1.2199.nptl) and it works like a charm. The only difference is /dev/ttyACM0 for CentOS and /dev/input/ttyACM0 for the Fedora. Any help would be appreciated. Tank's. Fernando Lança Some debug info: CentOS: /var/log/messages --> Aug 11 17:47:34 c4 kernel: usb 3-3: new full speed USB device using address 4 Aug 11 17:47:35 c4 kernel: drivers/usb/class/cdc-acm.c: Ignoring extra header Aug 11 17:47:35 c4 kernel: cdc_acm 3-3:1.0: ttyACM0: USB ACM device Aug 11 17:47:35 c4 kernel: usbcore: registered new driver cdc_acm Aug 11 17:47:35 c4 kernel: drivers/usb/class/cdc-acm.c: v0.23:USB Abstract Control Model driver for USB modems and ISDN adapters ............. Aug 11 17:50:04 c4 ifup-ppp: pppd started for mymodem on /dev/ttyACM0 at 57600 Aug 11 17:50:04 c4 pppd[3019]: pppd 2.4.2 started by root, uid 0 Aug 11 17:50:05 c4 wvdial[3034]: WvDial: Internet dialer version 1.54.0 Aug 11 17:50:05 c4 wvdial[3034]: Initializing modem. Aug 11 17:50:05 c4 wvdial[3034]: Sending: ATZ Aug 11 17:50:10 c4 wvdial[3034]: Sending: ATQ0 Aug 11 17:50:11 c4 wvdial[3034]: Re-Sending: ATZ Aug 11 17:50:16 c4 wvdial[3034]: Modem not responding. Aug 11 17:50:16 c4 pppd[3019]: Connect script failed Aug 11 17:50:17 c4 pppd[3019]: Exit. /etc/wvdial.conf [Modem0] Modem = /dev/ttyACM0 Baud = 57600 SetVolume = 0 Dial Command = ATDT Init1 = ATZ Init3 = ATM0 FlowControl = Hardware (CRTSCTS) [Dialer mymodem] Username = XXXXXXXXX Password = xxxx Phone = XXXXX Stupid Mode = 1 Inherits = Modem0 ----------------------------------------- Fedora Core 1: /var/log/messages --> Aug 11 09:54:58 c1 kernel: usb.c: USB device not accepting new address=9 (error=-110) Aug 11 09:54:59 c1 kernel: hub.c: new USB device 00:1d.0-1, assigned address 10 Aug 11 09:54:59 c1 kernel: ttyACM0: USB ACM device Aug 11 09:55:03 c1 kernel: usb-uhci.c: ENXIO 80000a80, flags 0, urb eaa4fa00, burb eaa4f480 Aug 11 09:55:03 c1 usb.agent[11124]: missing kernel or user mode driver acm Aug 11 09:55:03 c1 usb.agent[11125]: missing kernel or user mode driver acm .......... Aug 11 09:55:51 c1 ifup-ppp: pppd started for mymodem on /dev/input/ttyACM0 at 57600 Aug 11 09:55:52 c1 pppd[12546]: pppd 2.4.1 started by root, uid 0 Aug 11 09:55:53 c1 wvdial[12567]: WvDial: Internet dialer version 1.53 Aug 11 09:55:53 c1 wvdial[12567]: Initializing modem. Aug 11 09:55:53 c1 wvdial[12567]: Sending: ATZ Aug 11 09:55:53 c1 wvdial[12567]: ATZ Aug 11 09:55:53 c1 wvdial[12567]: OK Aug 11 09:55:53 c1 wvdial[12567]: Sending: ATM0 Aug 11 09:55:53 c1 wvdial[12567]: ATM0 Aug 11 09:55:53 c1 wvdial[12567]: OK Aug 11 09:55:53 c1 wvdial[12567]: Modem initialized. /etc/wvdial.conf [Modem0] Modem = /dev/input/ttyACM0 Baud = 57600 SetVolume = 0 Dial Command = ATDT Init1 = ATZ Init3 = ATM0 FlowControl = Hardware (CRTSCTS) [Dialer mymodem] Username = XXXXXXXX Password = xxxxx Phone = xxxx Stupid Mode = 1 Inherits = Modem0