I try to use Nokia Communicator 9500 as a modem for my Red Hat 7.2
Linux laptop. I try to use the USB cable that is supplied with the
9500 to connect my laptop and the 9500.

When I plug in the communicator, /var/log/messages displays the

Mar 5 16:01:15 think kernel: hub.c: USB new device connect on bus1/1,
assigned device number 2
Mar 5 16:01:15 think kernel: usb.c: USB device 2 (vend/prod
0x421/0x405) is not claimed by any active driver.
Mar 5 16:01:18 think kernel: usb.c: registered new driver acm
Mar 5 16:01:18 think kernel: acm.c: v0.21:USB Abstract Control Model
driver for USB modems and ISDN adapters

Below is an excerpt from /proc/bus/usb/devices:

T: Bus=01 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#= 2 Spd=12 MxCh= 0
D: Ver= 1.10 Cls=02(comm.) Sub=00 Prot=00 MxPS=64 #Cfgs= 1
P: Vendor=0421 ProdID=041a Rev= 0.00
S: Manufacturer=Nokia
S: Product=Nokia 9500 (RNDIS)
S: SerialNumber=0123456789
C:* #Ifs= 2 Cfg#= 1 Atr=80 MxPwr=100mA
I: If#= 0 Alt= 0 #EPs= 1 Cls=02(comm.) Sub=02 Prot=ff Driver=(none)
E: Ad=84(I) Atr=03(Int.) MxPS= 64 Ivl=128ms
I: If#= 1 Alt= 0 #EPs= 2 Cls=0a(data ) Sub=00 Prot=00 Driver=(none)
E: Ad=82(I) Atr=02(Bulk) MxPS= 64 Ivl=0ms
E: Ad=03(O) Atr=02(Bulk) MxPS= 64 Ivl=0ms

Why does it say "Driver=(none)" on the I: line?

When I try to connect via an ACM tty with C-Kermit, I get the
following error:

C-Kermit>set port /dev/ttykoe4
/dev/ttykoe4: Invalid argument

The device file /dev/ttykoe* have major number 166 (ACM):

$ ls -l /dev/ttykoe4
crw-rw-rw- 1 root root 166, 4 Mar 12 16:12 /dev/ttykoe4

I'm using Red Hat 7.2 with kernel 2.4.18-19.7.x on IBM Thinkpad 560Z.
The Communicator has software version 4.51(0).

See More: Use Nokia 9500 Communicator as a modem for Linux with USB cable