The PPP daemon has died: A modem hung up the phone (exit code = 16) → LCP: timeout sending Config-Requests

[Bill Yikes]

/etc/wvdial.conf:
===8<------------------------------
[Dialer Defaults]
StupidMode = 1
Modem Type = Analog Modem
Baud = 9600
New PPPD = yes
Modem = /dev/ttyUSB0
ISDN = 0
Init1 = ATZ
Init2 = ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0

[Dialer Orange]
Init3 = AT+CGDCONT=1,"IP","mworld.be",,0,0
Phone = *99#
Mcc = 206
Mnc = 10
Username = ''
Password = ''
Carrier Check = off
------------------------------>8===

execution:
===8<------------------------------
$ eject /dev/sr0
$ wvdial Orange
--> WvDial: Internet dialer version 1.61
--> Initializing modem.
--> Sending: ATZ
OK
--> Sending: ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
OK
--> Sending: AT+CGDCONT=1,"IP","mworld.be",,0,0
AT+CGDCONT=1,"IP","mworld.be",,0,0
OK
--> Modem initialized.
--> Sending: ATDT*99#
--> Waiting for carrier.
ATDT*99#
CONNECT 3600000
--> Carrier detected. Waiting for prompt.
--> Don't know what to do! Starting pppd and hoping for the best.
--> Starting pppd at…
--> Pid of pppd: 84797
--> Using interface ppp0
--> Disconnecting at…
--> The PPP daemon has died: A modem hung up the phone (exit code = 16)
--> man pppd explains pppd error codes in more detail.
--> Try again and look into /var/log/messages and the wvdial and pppd man pages for more information.
--> Auto Reconnect will be attempted in 5 seconds
------------------------------>8===

From the error codes list in “man pppd”:

  16 The link was terminated by the modem hanging up.

/var/log/messages:
===8<------------------------------
$timestamp $host pppd[84797]: pppd 2.4.9 started by $user, uid 0
$timestamp $host pppd[84797]: Using interface ppp0
$timestamp $host pppd[84797]: Connect: ppp0 <--> /dev/ttyUSB0
$timestamp $host pppd[84797]: LCP: timeout sending Config-Requests
$timestamp $host pppd[84797]: Connection terminated.
$timestamp $host pppd[84797]: Modem hangup
$timestamp $host pppd[84797]: Exit.
------------------------------>8===

The modem is a Huawei E220. I added “debug” to /etc/ppp/options but this failed to increase verbosity in /var/log/messages. When another machine connects to the same wireless broadband provider, CHAP is automatically negotiated and successfully used, FWIW.