求教GPRS拨号问题

问题现象:

Starting GPRS connect script
Setting APN
Dialing *99***1# .....
Dialing Done!
CONNECT Done!
Serial connection established.
Using interface ppp0
Connect: ppp0 <--> /dev/ttyS0
Remote message: TTP Com PPP - Password Verified OK
PAP authentication succeeded
Received bad configure-rej:  81 06 00 00 00 00 81 06 00 00 00 00
Received bad configure-rej:  81 06 00 00 00 00 81 06 00 00 00 00
Received bad configure-rej:  81 06 00 00 00 00 81 06 00 00 00 00




求教原因???????