GTP_ECHO_REQ
gtp0_build_echo_msg(gtp0_h, GTP_ECHO_REQ);
gtp1u_build_echo_msg(gtp1u_h, GTP_ECHO_REQ);
if (gtp0->type == GTP_ECHO_REQ && gtp->sk_created)
if (gtp1->type == GTP_ECHO_REQ && gtp->sk_created)