а у меня вот с таким конфигом работает...правда девайс - ADU-300:tupik# cat ppp.conf
default:
set log Phase Chat LCP IPCP CCP tun command
# set speed 921600
set speed 460800
set speed 230400
# set speed 115200
set timeout 160
enable dns
disable ipv6cp
disable pred1 deflate deflate24 protocomp acfcomp shortseq vj
deny pred1 deflate deflate24 protocomp acfcomp shortseq vj
bwc:
# set device /dev/ucom0
set device /dev/ttyU0
set phone \#777
set dial "ABORT BUSY ABORT NO\\sCARRIER TIMEOUT 5 \"\" AT OK-AT-OK ATE1Q0L1M1 OK \\dATDT\\T TIMEOUT 40 CONNECT"
set authname bwc
set authkey bwc
set ifaddr 10.0.0.1/0 10.0.0.2/0 255.255.255.0 0.0.0.0
add default HISADDR