Hi James et al, That was perfect. I changed the device to /dev/ttyUSB0 from /dev/ttyUSB1, and our entire lab was on cloud nine. Thanks a ton for the extraordinary help. Regards Murali On Thu, 2010-03-04 at 07:30 +1100, James Cameron wrote: > On Wed, Mar 03, 2010 at 11:41:15PM +0900, Murali K. Vemuri wrote: > > Jan 1 00:02:37 (none) local2.info chat[109]: send (AT^M) > > Jan 1 00:02:37 (none) local2.info chat[109]: send (AT > > +CGDCONT=1,"ip","web.sktelecom.com",,,^M) > > Jan 1 00:02:38 (none) local2.info chat[109]: send (ATDT*98#^M) > > Jan 1 00:02:38 (none) local2.info chat[109]: expect (CONNECT) > > Jan 1 00:03:23 (none) local2.info chat[109]: alarm > > There's no evidence in that chat log that you are receiving anything > back from the modem. You should receive OK in response to AT and > AT+CGDCONT. Can you confirm that with a manual connection between > keyboard and modem? > > A common cause of this is modems that provide two USB endpoints; one for > firmware update, one for communications. The firmware update endpoint > may not respond. For one modem, I fixed this by using the next device > name; /dev/ttyUSB1 instead of /dev/ttyUSB0. > > Otherwise, the sequence looks acceptable. For a sequence that I've > tested with a different modem, but which works with every other modem > I've tried, see: > > http://quozl.linux.org.au/darcs/eee-bpw/etc/chatscripts/bpw > > In this particular instance, an additional check AT+CGATT? is done to > verify that the modem has attached to the network ... before attempting > a connection. > -- 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