I'm running PPP over an EVDO (Verizon cellular) PCMCIA modem.  (Well, 
since the thing appears as a USB hub maybe it's Cardbus.)  Here are the 
attach messages:

Dec 13 17:48:42 berkshire dhclient: dhclient
Dec 13 17:48:43 berkshire ifd: wm0 interface-Up (0.0.0.0 0.255.255.255) --------------------
cbb0: wait took 0.020175s
ohci0 at cardbus0 function 0: NEC USB Host Controller (rev. 0x43)
ohci0: interrupting at 11
ohci0: OHCI version 1.0
usb4 at ohci0: USB revision 1.0
uhub4 at usb4
uhub4: NEC OHCI root hub, class 9/0, rev 1.00/1.00, addr 1
uhub4: 1 port with 1 removable, self powered
ohci1 at cardbus0 function 1: NEC USB Host Controller (rev. 0x43)
ohci1: interrupting at 11
ohci1: OHCI version 1.0
usb5 at ohci1: USB revision 1.0
uhub5 at usb5
uhub5: NEC OHCI root hub, class 9/0, rev 1.00/1.00, addr 1
uhub5: 1 port with 1 removable, self powered
umodem0 at uhub4 port 1 configuration 1 interface 0
umodem0: Curitel Communications, Inc. Curitel Communications, Inc., rev 1.10/0.00, addr 2, iclass 2/2
umodem0: data interface 1, has CM over data, has break
umodem0: status change notification available
ucom0 at umodem0

A lot of stuff just works.  Sometimes, though, when the connection 
terminates (for no good or even apparent reason, but that's a separate
story), pppd just sits there, even if I hit ^C several times:

LCP terminated by peer
Connect time 3.7 minutes.
Sent 33210 bytes, received 68196 bytes.
Modem hangup
Connection terminated.
^CTerminating on signal 2
^CTerminating on signal 2

Just now, I only got it to die by sending it *two* SIGKILLs.  
Sometimes, it doesn't want to die at all.  Any suggested fixes or 
diagnostics?  I'm running a very recent -current kernel.



		--Steven M. Bellovin, http://www.cs.columbia.edu/~smb