не возможно соедениться не из под rootа вот лог: May 12 19:52:44 localhost pppd[2892]: pppd 2.4.2 started by vv, uid 1000 May 12 19:52:44 localhost pppd[2892]: Using interface ppp0 May 12 19:52:44 localhost pppd[2892]: Connect: ppp0 <--> /dev/ttyS0 May 12 19:52:48 localhost pppd[2892]: Remote message: Password validation failure May 12 19:52:48 localhost pppd[2892]: Connection terminated. May 12 19:52:48 localhost pppd[2892]: Exit.