[USR-TC] L2TP with IPSEC

Hi, I'm trying to set up a tunnel L2TP with IPSEC between the HARC (LAC) and a router cisco (LNS). When I test a connexion a have the following error on the cisco : CRYPTO-4-RECVD_PKT_NOT_IPSEC: Rec'd packet not an IPSEC packet. I launched the monitor protocol L2TP on the HARC, the tunnel didn't establish. the router did not reply to the L2TP start session request. I didn't know which parameter a forget on the HARC. Is there a command to enable the IPSEC? I created the policy file and active it. I applied the policy file to an user. Thanks, Yan